Question

como resolvo
(5x+2)² - (3x-4)² =

Answer 1

Boa noite Demileide!

Solução!


$(5x+2)^{2} -(3x-4)^{2}$

$(25 x^{2} +10x+10x+4)-(9 x^{2} -12x-12x+16)$

$(25 x^{2} +20x+4)-(9 x^{2} -24x+16)$

$16 x^{2} +44x-12=0$

Aplicando a formula de Bhaskara.

$Formula~~x= \dfrac{-b\pm \sqrt{b^{2}-4.a.c } }{2.a}$

$x= \dfrac{-44\pm \sqrt{44^{2}-4.16.(-12) } }{2.16}$

$x= \dfrac{-44\pm \sqrt{1936+768} }{32}$

$x= \dfrac{-44\pm \sqrt{2704} }{32}$

$x= \dfrac{-44\pm 52 }{32}$

$x_{1} = \dfrac{-44+ 52 }{32}= \dfrac{8}{32} = \dfrac{1}{4}$

$x_{2} = \dfrac{-44-52 }{32}= \dfrac{-96}{32} = -3$

$\boxed{Resposta: x_{1}= \dfrac{1}{4} ~~ ~~x_{2}=-3 }$

Boa noite!
Bons estudos!

Answer 2

(5x+2)² - (3x-4)² =

(5x + 2x2) - (3x-4x4)=
 (5x +4) - (3x-8)=
5x +4 - 3x - 8
5x- 3x = 8 - 4
2x = 4
x=4  ÷ pra 2
x=2

Espero ter ajudado :)