The solution of quadratic equation of one variable It is known that 4x ^ 2-12x + y ^ 2 + 2Y + 10 = 0 Find the value of 2x + Y / 2x-y It's not interesting at all

The solution of quadratic equation of one variable It is known that 4x ^ 2-12x + y ^ 2 + 2Y + 10 = 0 Find the value of 2x + Y / 2x-y It's not interesting at all

The formula on the left side of the original equation is as follows:
[(2x)^2-2×3×2x+3^2]+[y^2+2×1×x+1^2]=0
Namely:
(2x-3)^2+(y+1)^2=0
So there are: 2x-3 = 0 and y + 1 = 0
That is: x = 3 / 2, y = - 1;
So (2x + y) / (2x-y) = 2 / 4 = 0.5

Help me, junior three quadratic equation solutions
There is a two digit number. The sum of the two digits is 6. The product of the two digits is equal to 1 / 3 of the two digits
I know to set one digit to X and ten digits to 6-x
Then x (6-x) = one third of the two digits
But I don't know how to solve the two digit equation?

If we set the number of bits to X and the number of tens to 6-x, then:
3x(6-x)=10(6-x)+x
18x-3x^2=60-10x+x
3x^2-27x+60=0
x^2-9x+20=0
(x-5)(x-4)=0
x1=5 x2=4
It could be five or four,
This number is 15 or 24

Xiao Li and Xiao Lan are good friends. She often helps her review her lessons
Revise the wrong sentence

The subject is not clear who "she" and "she" refer to
She often helps Xiao Lan review her lessons

Some questions about English in the second semester of junior one~
1.( )The postman ______ people's letters every day.
A.makes B.writes C.takes D.brings
2.( )What's your father doing?
He's talking____ my teacher now.
A.for B.with C.at D.of.
He wants to be a football player
______ he_______ to be a football player?
4. My father works in the bank
My father ______ ______ in the bank.
5. What is your brother
What ______ your brother ______ ?
6.My sister wants to be __ a reporter__ (ask questions about the underlined part)
———— ————sister want to ______ .

1.( D )The postman ______ people's letters every day.
A.makes B.writes C.takes D.brings
2.(B )What's your father doing?
He's talking____ my teacher now.
A.for B.with C.at D.of.
He wants to be a football player
Doe she___ want____ to be a football player?
4. My father works in the bank
My father _ doesn't_ __ work____ in the bank.
5. What is your brother
What __ does____ your brother __ work____ ?
6.My sister wants to be __ a reporter__ (ask questions about the underlined part)
—What——— ——does——sister want to ___ be___ .

What is the function of a compass ruler to make a line segment equal to a known line segment?

For drawing with ruler and compasses, the ruler can only draw a straight line, not measure the distance. The compasses can only draw an arc, not measure the distance. To make a line segment equal to a known line segment, the circle is used to specify the distance, because the compasses can copy the existing length

A suit costs 1280 yuan. The price of pants is 60% of the price of top. How much more is the price of top than that of pants

1280 / (1 + 60%) = 800 yuan and times the problem 1280 is the total price of the jacket and pants. 1 + 60% is the division of the two corresponding percentages to get unit 1, which is the unit price of the jacket. Then the price of the pants is 1280-800 = 480 yuan, 800-480 = 320 yuan more than the pants, or 800 * (1-60%) is 40% more than the pants

In the equal ratio sequence, the common ratio is an integer, a1 + A4 = 18, A2 + a3 = 12. Find the sum of the first eight terms S8

a1+a4=18a1+a1q^3=18a1(1+q^3)=18a1=18/(1+q^3)[q≠-1]a2+a3=12a1q+a1q^2=12a1(q+q^2)=12a1=12/(q+q^2)[q≠-1]18/(1+q^3)=12/(q+q^2)3q+3q^2=2+2q^32(1+q^3)-3(q+q^2)=02(1+q)(1-q+q^2)-3q(1+q)=0(1+q)(2-2q+2q^2-3q...

5080 ml=______ Liter=______ Cubic decimeter

5080 ml = 5.08 L = 5.08 cubic decimeter

The motorcade transported goods and materials to the disaster area, traveling 60 kilometers per hour and 6.5 hours to the destination, and traveling 78 kilometers per hour to the destination. How long will it take them to return to their destination?

60 × 6.5 / 78 = 390 / 78 = 5 (hours) a: they can return to their departure place in 5 hours

What is the common unit of measurement

Common units of measurement and their conversion
1. Length unit:
1 inch (in) = 0.0254 M 1 mile (me) = 1609.35 M
1 foot (FT) = 0.3048 M 1 micron (μ m) = 10-6 M
2. Area unit:
1 in2 = 6.452×10-4 m2 1 mi2 = 2.59×106 m2
1 ft2 = 0.0929 m2 1 km2 = 106 m2
3. Volume unit:
1 liter (L, DM3) = 10-3 M3
1 in3 = 0.01639 L 1 usgal = 3.78543 L
1 FT3 = 28.317 L 1 UK gal = 4.54374 L
1 US quart (QT) = 0.94636 L 1 US barrel (BBL, oil) = 158.98 L
4. Quality unit:
1 Newton (n) = 0.102 kg 1 pound (LB) = 0.454 kg
5. Pressure unit:
1 kgf / cm2 = 0.0981 MPa, 1 mmh2o = 9.81 × 10-6 MPa
1 bar = 0.1 MPa, 1 mm Hg = 1.333 × 10-3 MPa
1 standard atmospheric pressure (ATM) = 0.1013 MPa, 1 inch water column (inh2o) = 2.49 × 10-4 MPa
1 lb / in2 (PSI, lb / in2) = 6.89 × 10-3 MPa, 1 foot water column (fth2o) = 2.984 × 10-3 MPa
1 oz / in2 (ozf / in2) = 4.31 × 10-4 MPa, 1 in Hg = 3.386 × 10-3 MPa
6. Temperature unit:
- 32)×5/9 = ℃ K - 273.15 = ℃
7. Flow unit:
7.1 volume flow unit
1 m3/h = 0.01667 m3/min 1 UKgal/min = 4.546×10-3 m3/min
1 L/min = 10-3 m3/min 1 USgal/min = 3.785×10-3 m3/min
1 FT3 / h = 4.719 × 10-4 m3 / min 1 U.S. barrel / day (bbl / D) = 1.104 × 10-4 m3 / min
7.2 mass flow unit
1 kg/h = 0.01667 kg/min 1 lb/h = 7.56×10-3 kg/min
CV value: the constant value of water flow (US Gal / min) obtained by flowing through a valve with a differential pressure of 1 psi at 60?. (CV × 1000 = L / min)
Kv value: the constant value of water flow (L / min) through a valve with a differential pressure of 1kgf / cm2 at 20 ℃
Kv value: the constant value of water flow (m3 / min) at 20? Through a valve with a differential pressure of 1kgf / cm2
S value: effective cross-sectional area of pneumatic components (mm2)
S. T.P = standard temperature and pressure (0 ℃ and 101.3 kPa absolute pressure)
N. T.P = normal temperature and pressure (20 ℃ and 101.3 kPa absolute pressure)
M. S.C = metric standard case (15 ℃ and 101.3 kPa absolute pressure)
Anr = temperature: 20 ℃ and relative humidity: 65%
Conversion between discharge coefficients: CV = 1.17 kV s = 18.45 CV
8. Concentration unit:
1 μ g / m3 = 10-3 mg / m3, 1 ppm (by weight) = 1.198 mg / m3
1 lb / FT3 = 1.6108 × 107 mg / m3, 1 ppm (by volume, 20 ℃) = m (molecular weight) / 22.4 mg / m3
9. Density unit:
1 lb/in3 = 2.768×10-4 kg/m3(g/L) = 27.68 g/cm3 1 lb/UKgal = 99.8 kg/m3(g/L) = 0.0998 g/cm3
1 lb/ft3 = 16.02 kg/m3(g/L) = 0.01602 g/cm3 1 lb/USgal = 119.8 kg/m3(g/L) = 0.1198 g/cm3
10. Humidity unit:
Dew point ℃ absolute humidity g / m3 volume ratio ppmv weight ratio (in air) ppmw relative humidity (20 ℃)%
-70 0.00207 2.5 1.64 0.001
-60 0.00857 11 6.59 0.005
-50 0.0312 39 24.2 0.02
-40 0.102 127 79.1 0.05
-30 0.301 376 134 0.2
-20 0.816 1020 635 4
-10 2.06 25602 1590 11
0 4.84 6020 3800 26
10 9.21 12100 7729 52
20 18.5 23100 100
30 36.6 41800
40 58.5 73000
11. Heat and work units:
1 calit = 4.1868 J (n? M) energy [quantity], work, heat: SI unit name? Joule [ear]
1 calth = 4.1840 J power, radiant flux: SI unit name? Watt
1 20 ℃ cal 20 = 4.1816 J specific heat capacity: SI unit name? Joule [watt] per kilogram Kelvin
115 ℃ cal (cal15) = 4.1855 J 1kcal / kg? ℃ [kcalit / (kg? ℃)] = 4186.8 J / (kg? K)
1 BTU = 1.05506 × 103 J, 1 kcalth / (kg? ℃) = 4184 J / (kg? K)
1 kWh (kW? H) = 3.6 × 106 j 1 BTU / (LB?) = 4186.8 J / (kg? K)
1 KGF? M / S = 9.80665w = 9.80665n? M / s heat transfer coefficient: SI unit name? Watt [t] Kelvin per square meter
1 metric horsepower (PS) = 7.35499 × 102 W, 1 kcalit / (cm2? ℃) = 4.1868 × 107 w / (M2? K)
1 British horsepower (PS) = 745.7 w thermal conductivity: SI unit name? Watts per meter Kelvin
1 ft? LBF / S = 1.35582 w 1 kcalit / (cm? ℃) = 4.1868 × 105 w / (M? K)
12. Force unit:
KGF, KP, kilopound = 9.80665 n, 1 pound = 4.44822 n
1 LBF = 4.448 n 1 dyne = 10-5 n
13. Viscosity unit:
13.1 dynamic viscosity η unit
1 KGF? S / m2 = 9.81 kg / (M? S) = 9.81 Pa? S 1 g / (cm? S) [poise, P] = 0.1 Pa? S
1 kg / (M? H) = 2.778 × 10-4 Pa? S 1 g / (M? S) [centipoise, CP] = 10-3 Pa? S
1 lb/(ft?s) = 1.488 Pa?s 1 lbf?s/ft2 = 47.88 Pa?s
13.2 kinematic viscosity V unit
υ = η/ρ υ-cSt(mm2/s),η-10-3 Pa?s=1cP,ρ-g/cm3 1 m2/h = 2.778×10-4 m2/s
1 cm2 / S (s, st) = 10-4 m2 / s, 1 ft2 / S = 9.29 × 10-2 m2 / S
1 mm2 / S (CST) = 10-6 m2 / s, 1 ft2 / S = 2.58 × 10-5 m2 / S
13. Electronic unit of measurement:
Charge [quantity]? Coulomb [C], current? Ampere I, potential (voltage, electromotive force)? Volt [t] V, resistance [(inductance, capacitance, resistance)]? Ohm [M] Ω,
Resistivity? M Ω? M, resistance temperature coefficient? ℃ - 1, inductance? H, capacitance? F, frequency? Hz, period? S,
Active power? W, reactive power? VaR, apparent power? VA, power factor? Cos φ, energy [work, heat]? J
Magnetic energy? Weber? WB, magnetic flux density [magnetic induction]? Tesla? T, permeability? H / m, Newton? N, torque? M? N? M
1 a = 103 Ma = 106 μ a 1 Maxwell (MX) = 10-8 WB
1 F = 106 μ f = 1012 pf 1 Gauss (g) = 10-4 t
1 m = 106 mm2 / M 1 eV = 1.60207 × 10-19 J