Question

Indentifique as sentenças verdadeiras e corrija as falsas a) (x-4).(x-7)=x-11x+28 b) (x-10).(x+9)=x-x-90 c) (x+5).(x-12)=x-12x+60

Answer 1

a) (x - 4) (x - 7) = x - 11x + 28
$x^2 - 7x - 4x + 28 = x - 11x + 28 \\ x^2 - 11x + 28 = x - 11x + 28$

Falsa.

b) (x - 10) (x + 9) = x - x - 90
$x^2 + 9x -10x - 90 = x - x - 90 \\ x^2 - x - 90 = x - x - 90$

Falsa

c) (x + 5) (x - 12) = x - 12x  + 60
$x^2 - 12x + 5x - 60 = x - 12x + 60 x^2 - -7x - 60 = x - 12x + 60$

Falsa