Question

f. (8 - x)(x + 7) + 2x(x - 6) = 2(x-6)(x+7)


ayuda​

Answer 1

Explicación paso a paso:

$(8 - x)(x + 7) + 2x(x - 6) = 2(x - 6)(x + 7)$

8x+56-x^2-7x+2x^2-12x=(2x-12)(x+7)

8x+56-x^2-7x+2x^2-12x= 2x^2 + 14x-12x-84

8x +56- x^2 - 7x= 14x-84

x+56-x^2-14x+84=0

-13x+140-x^2

13x-140+x^2

x^2+13x-140=0

x^2+ 20x-7x -140=0

x(x+20) -7x(x+20)=0

(x+20) (x-7)=0

x+20=0

x-7=0

x1=-20

x2=7