Question

Me ajudem por favor!
(50+2x) . (40+2x) = 1000

Answer 1

Resposta:

2000+100x+80x+4x^2=1000

4x^2+180x+1000=0             divida por 4 todos os termos

x^2+45x+250=0

use Δ=b^2-4ac

x=(-b+-√Δ)/2a

Explicação passo-a-passo:

Answer 2

Resposta:

$(50+2x) * (40+2x) = 1000\\\\2000+180x+4x^2=1000\\\\2000+180x+4x^2-1000=1000-1000\\\\4x^2+180x+1000=0\\\\x_{1,\:2}=\frac{-180\pm \sqrt{180^2-4\cdot \:4\cdot \:1000}}{2\cdot \:4}\\\\x_{1,\:2}=\frac{-180\pm \:20\sqrt{41}}{2\cdot \:4}\\\\x_1=\frac{-180+20\sqrt{41}}{2\cdot \:4},\:x_2=\frac{-180-20\sqrt{41}}{2\cdot \:4}\\\\x=\frac{5\left(\sqrt{41}-9\right)}{2}\\\\\:x=-\frac{5\left(9+\sqrt{41}\right)}{2}$