А)7+x(x-1)=x^2-1 б)3(2x-4)=2x-(5x+9)

Question

А)7+x(x-1)=x^2-1 б)3(2x-4)=2x-(5x+9)

Answer 1

7 + x^2 - x = x^2 - 1
7 - x = - 1
- x = - 1 - 7
- x = - 8 
x = 8 

6x - 12 = 2x - 5x - 9 
6x - 12  = - 3x - 9
6x + 3x = 12 - 9
9x = 3
x = 3/9
x = 1/3

Answer 2

А). 7+x^2-x=x^2-1, x^2-x-x^2= -1-7, -x= -8, x=(-8)/(-1)=8. б).  6x-12=2x-5x-9, 6x-2x+5x= -9+12, 9x=3, x=3/9=1/3.