4x-7 * 8 = 4 solution equation

4x-7 * 8 = 4 solution equation

4x-7*8=4
4x-56=4
4x=4+56
4x=60
x=15

There are three simple calculations as follows: (3 / 8 + 1 / 27) × 19 solutions of 8 + 27: 5x-5 × 1 / 4 = 8 / 5
A machine tool factory produced 480 machine tools in the first half of the year, and completed 3 / 5 of the annual plan. According to this calculation, how many machines will be produced in the next year to complete the task?

(3 / 8 + 1 / 27) × 8 + 19 / 27 = 3 / 8 × 8 + 1 / 27 × 8 + 19 / 27 = 3 + (8 / 27 + 19 / 27) = 3 + 1 = 4 solution equation: 5x-5 × 1 / 4 = 8 / 55x-5 / 4 = 8 / 55x = 8 / 5 + 5 / 45x = 57 / 20x = 57 / 100 480 ÷ 3 / 5-480 = 320 [mathematics tutoring group] answer for you! If you don't understand, please ask, if you understand, please click "select as satisfactory answer!..."

Given X-1 | x = 5, find the value of x ^ 2-5x-7

From the known denominator to get: x square - 5x = 1
So x ^ 2-5x-7 = 1-7 = - 6

If 2x-5y = 0 and X ≠ 0, then the value of 6x − 5y6x + 5Y is______ ．

From 2x-5y = 0, we can get 5Y = 2x (x ≠ 0), 6x − 5y6x + 5Y = 6x − 5x6x + 2x = 12 (x ≠ 0)

If x / 3Y = Y / (2x-5y) = (6x-15y) / X
X / 3Y = Y / (2x-5y) = (6x-15y) / X find (4x ^ 2-5xy + 6y ^ 2) / (x ^ 2-2xy + 3Y ^ 2) =?

x/3y=y/2x-5y
2x^2-5xy-3y^2=0
(x-3y)(2x+y)=0①
x/3y=6x-15y/x
x^2-18xy+45y^2=0
(x-3y)(x-15y)=0②
y/2x-5y=6x-15y/x
xy=3(2x-5y)^2
(x-3y)(12x-25)=0③
If (1), (2) and (3) are true at the same time,
x-3y=0,x=3y
(4x^2-5xy+6y^2)/(x^2-2xy+3y^2)
=[4(3y)^2-5*(3y)*y+6y^2]/[(3y)^2-2*(3y)*y+3y^2]
=9/2

If there are only two points on the circle (x-3) 2 + (y + 5) 2 = R2 and the distance from the two points to the straight line 4x-3y = 2 is equal to 1, then the value range of radius R is ()
A. （4，6）B. [4，6）C. （4，6]D. [4，6]

∵ the distance from the center of the circle P (3, - 5) to the straight line 4x-3y = 2 is equal to | 12 − 3 · (- 5) − 2 | 16 + 9 = 5, from | 5-r | 1 to get & nbsp; & nbsp; 4 | R | 6, so select a

It is proved that the value of - 10 & # 178; + 7x-4 is always less than 0

"- 10 & # 178; + 7x-4" is that right? Is that - 10x & # 178; + 7x-4
-10x²+7x-4
=-10(x²-7/10*x)-4
=-10(x²-7/10*x+49/400)-4+49/40
=-10(x-7/20)²-111/40

It is known that the two opposite numbers of the equation x & # 178; - (M & # 178; - 4) x + 1-m = 0 about X are obtained

That is, the coefficient of the first term is 0,
We get M & # 178; - 4 = 0
We get: M = 2 or - 2
When m = 2, the equation is X & # 178; - 1 = 0, which is consistent with;
When m = - 2, the equation is X & # 178; + 3 = 0
In conclusion, M = 2

On the two real number roots of the equation M & # 178; X & # 178; + (2m + 3) x + 1 = 0 of X, α and β are opposite to each other
In addition, X & # 178; + 2 (a + m) + 2a-m & # 178; + 6m-4 = 0 has roots greater than 0 and less than 2
(1) Find the value of α & # 178; - β & # 178
(2) The scope of a job

(1) Because the two real number roots of the equation M & # 178; X & # 178; + (2m + 3) x + 1 = 0, α and β are opposite to each other, m ≠ 0, so the sum of the two numbers is 0, so α + β = 0, α & # 178; - β & # 178; = (α + β) (α - β) = 0 * (α - β) = 0 (2) because α + β = 0, we get (2m + 3) / m ^ 2 = 0 from Weida's theorem, so

It is known that the product of the two equations X & # 178; + 3 (2m-1) x + 9m & # 178; + 6 = 0 is twice the sum of the two equations, and the value of the real number m is obtained

By using Veda's theorem, we get that 9m ^ 2 + 6 = 2 (- 6m + 3)
Then 9m ^ 2 + 6 = - 12m + 6
9m^2+12m=0
m1=0,m2=-4/3