The system of Equations 3 (x + y) − 4 (x − y) = 4x + Y2 + X − y6 = 1

The system of Equations 3 (x + y) − 4 (x − y) = 4x + Y2 + X − y6 = 1

3 (x + y) − 4 (x − y) = 4 & nbsp; & nbsp; ① x + Y2 + X − y6 = 1 & nbsp; & nbsp; & nbsp; ②, 3 (x + y) + (X-Y) = 6 from ②, 5 (X-Y) = 2 from ③ - ①, that is, X-Y = 25, substituting X-Y = 25 into ③, x + y = 2815, solving the equations x + y = 2815x − y = 25, x = 1715y = 1115

Given the equation 3x minus half, y = 1, first use the algebraic expression of X to express y, then write out the solution of the equation when x = - 1,0, half

3x-1/2y=1
6x-y=2
y=6x-2
When x = - 1, y = - 8-2 = - 8
When x = 0, y = 0-2 = - 2
When x = half, y = 3-2 = 1

When k is the value, the value of inequality 1 / 2 (KX + 8) > 3x is constant

1/2* kx+4>3x
When 1 / 2 * k = 3, k = 6, the left side is 3x + 4, the right side is 3x, and 3x + 4 > 3x holds

Calculation (- 3) / [(- 2 / 5) / (- 1 / 4)]
(- 3) / (- 2 / 5) / (- 1 / 4)
(- 9 / 14) / 2.5
Sorry, I have points in ten minutes.

(- 3) / (- 2 / 5) / (- 1 / 4)
=-3*5/2*4
=-30
(- 9 / 14) / 2.5
=-9/14*2/5
=-9/35

Finding the general term formula of 0 1 2 3 2 1 0 sequence

3 - | n-4 |, the system said that my answer was too simple, so I added two more sentences

The earth can be approximately regarded as a sphere. If V and R are used to represent the volume and radius of the sphere respectively, then v = four-thirds of the power of π R
The radius of the earth is 6x10 to the third power. How many cubic kilometers is its volume?

V=（4/3）*πR^3
R = 6x10 ^ 3km
V=（4/3）*3.14*(6*10^3)^3
V=（4/3）*3.14*216*10^9
V = 9.0432 * 10 ^ 11 cubic kilometers

Someone rides a motorcycle for a journey of 155 kilometers, which is divided into three different speeds and takes 3 hours to complete. The speed ratio of the three sections is 6:5:3. It is known that the speed of the first section is 60 kilometers and that of the third section is 10 kilometers. How much is the first and the second sections? (solve the practical problem with one variable linear equation)

From the speed ratio of the three sections is 6:5:3, the speed of the first section is 60 km per hour, it can be concluded that the speed of the second and third sections are 50 km / h and 30 km / h respectively. If the first section is x km, then the second section is (155-x-10) km = (145-x) km x / 60 + (145-x) / 50 + 10 / 30 = 3, so the first section is 70 km, The second section is (145-70) km = 75 km

A regular arrangement of the number table, with the formula containing N, n is a positive integer, indicating the number of N rows and N columns in the number table?
First column second column third column fourth column
First line 1 2 5 10
The second line 4 3 6 11
The third line 9 8 7 12
The fourth line 16 15 14 13

Y is the number of N rows and N columns
Y equals the square of n minus n plus 1
Y=N^2-(N-1)=N^2-N+1

Negative integers with absolute values greater than 1 and less than 4 have () and non negative integers with absolute values greater than 2 and less than 5 have ()

First: - 2, - 3
Second: 2, 3, 4, 5

As shown in the figure, given AE ⊥ BC in E, DF ⊥ BC in, AE = DF, ab = DC, what is the relationship between AC and BD? Can you prove it?

AC = DB it is proved that ∵ AE ⊥ BC is equal to e, DF ⊥ BC, ∵ AEB = ∠ DFC = 90 ° in RT △ Abe and RT △ DCF, ab = dcae = DF, ≌ RT △ Abe ≌ RT △ DCF & nbsp; (HL), ≌ Abe = DCF. In △ ABC and △ DCB, ab = DC ≌ Abe = dcfbc = CB, ≌ ABC ≌ DCB (ASA), ≌ AC = dB