The function image is used to solve x, and the written calculation test is: (1) 5x-3 = x + 2; (2) 0.5x-4 = 3x + 2

The function image is used to solve x, and the written calculation test is: (1) 5x-3 = x + 2; (2) 0.5x-4 = 3x + 2

(1) 5x-3 = x + 2, sort out and get the image of 4x-5 = 0 and function y = 4x-5 as shown in the figure below. From the image, we can see that the coordinates of the intersection of the line y = 4x-5 and the X axis are (54, 0), so the solution of the equation 5x-3 = x + 2 is x = 54. Test: substitute x = 54 into the left and right sides of the equation, and get the left = 5 × 54-3 = 134, right = 54 + 2 = 134, ∵ left = right, ∵ x = 54 is the solution of the equation 5x-3 = x + 2; (2) 0.5x-4 = 3x + 2, The image of 2.5x + 6 = 0 and the function y = 2.5x + 6 is shown in the figure below. From the image, we can see that the coordinates of the intersection of the line y = 2.5x + 6 and the X axis are (- 2.4, 0), so the solution of the equation 0.5x-4 = 3x + 2 is x = - 2.4
Given a = (- 2,5), B = (- 1,7), real numbers x, y satisfy XA + Yb = (- 1,2), find x, y
The sum of abscissa and ordinate is equal to minus one, and the sum of ordinate is equal to two
x=2.5y=0.85
On the relationship between two real roots of quadratic equation with one variable
Let a and B be the two real roots of the equation x & # 178; + x-2012 = 0, then what is the value of a & # 178; + 2A + B
A is the root of the equation
Then a ^ 2 + a-2012 = 0
a^2+a=2012
Weida theorem, a + B = - 1
Original formula = a ^ 2 + A + A + B = 2012-1 = 2011
What is the theoretical basis for the term shift of linear equation with one variable
It's the nature of the equation
If the same number (or formula) is added or subtracted from both sides of the equation, the equation still holds
Factorization (a ^ 2 + B ^ 2) - 4A ^ 2B ^ 2=
solution
(a-178; + b-178;) - 4a-178; b-178; - this one
=(a²+b²)²-(2ab)²
=(a²+2ab+b²)(a²-2ab+b²)
=(a+b)²(a-b)²
When the independent variable x takes what value, the value of function y = 2.5x + 1 and y = 5x + 17 are equal? What is the value of this function?
analysis
When 2.5x + 1 = 5x + 17
2.5x+16=0
2.5x=-16
x=--6.4
When x = -. 6.4, the function values are equal
The function value is - 15
Given the triangle ABC, vector AB = vector AC = 5, vector BC = 6. O is the inner part of the triangle, and AO = 5x + 6y
Too many conditions are lacking
If AB = AC = 5, BC = 6 in the triangle ABC, Ao = 2.5, and your X, y have no limited range, it is equivalent to giving the indefinite equation 5x + 6y = 2. There will be countless results
Extend the intersection of AO and BC at point E
AE is vertical and bisects BC,
BC = 6, so be = 3
Because AB = 5, AE = 4
OB=BE+OE,(BA=-5,BE=3)
AO=OB+BA
=BE+OE+BA
=3+(-5)+OE
AE=AO+OE
=3+(-5)+OE+OE
=(- 2) + o... expansion
Extend the intersection of AO and BC at point E
AE is vertical and bisects BC,
BC = 6, so be = 3
Because AB = 5, AE = 4
OB=BE+OE,(BA=-5,BE=3)
AO=OB+BA
=BE+OE+BA
=3+(-5)+OE
AE=AO+OE
=3+(-5)+OE+OE
=(-2)+OE+OE
Because AE = 4, 4 = (- 2) + OE + OE
2oe=6,
OE=3.
AO=5x+6y,
5x+6y=1,
So, x = 1, y = - 1
A quadratic equation with one variable has two equal real roots. Is there a formula
Quadratic equation of one variable has two equal real roots
B & sup2; - 4ac = 0
According to the definition of equation, a quadratic equation with one variable has two roots. If the two roots are equal, there are two equal real roots. If the discriminant of the equation is less than 0, there is no real root
Yes. Quadratic equation of one variable has two equal real roots
B & sup2; - 4ac = 0
x1=x2=-b/2a
Solving linear equation of one variable (2) -- removing bracket
The hearing scheme of step tariff for residential power consumption announced by a province is as follows:
First power second power third power
The monthly electricity consumption is below 210 degrees, the monthly electricity consumption is 210 to 350 degrees, and the monthly electricity consumption is above 350 degrees,
The price per kilowatt hour is 0.52 yuan. The price per kilowatt hour is 0.05 yuan higher than that of the first kilowatt hour. The price per kilowatt hour is 0.30 yuan higher than that of the first kilowatt hour
For example: if a household consumes 400 kwh per month, the electricity charge is
210 × 0.52 + (350-210) × (0.52 + 0.05) + (400-350) × (0.52 + 0.03) = 230 yuan
(1) According to this plan, Xiaohua's electricity charge in May is 138.84 yuan, please calculate Xiaohua's electricity consumption in May;
(2) According to this plan, please answer: if Xiaohua's electricity charge is a yuan in a month, what grade of electricity consumption is Xiaohua's?
(1) If the power consumption is x Du, there are: 210 * 0.52 = 109.2; (350-210) * (0.52 + 0.05) = 79.8; 109.2 + 79.8 = 189 > 138.84, so it is more than 210 degrees; no more than 350 degrees (x-210) (0.52 + 0.05) = 138.84-109.2; x-210 = 52; X = 262; so it is 262 degrees; (2) a < 109.2; it belongs to the first
Factorization: (a ^ 2 + B ^ 2-9) ^ 2-4a ^ 2B ^ 2