Question

como eu resolvo isso x(x+7)=7(x+7)

Answer 1

$x.(x+7)=7.(x+7)$

$x^2+7x= 7x+49$

$x^2+7x-7x=49$

$x^2=49$

$x= \sqrt{49}$

$x= 7$

Answer 2

$x(x+7)=7(x+7)$

$x^{2} +7x=7x+49$

$x^{2} +7x-7x=49$

$x^{2} =49$

$x= \sqrt{49}$

$x^{'} =7$

$x^{"} =-7$

S={-7,+7}