Question

x.(x-8)=3x²-4x forma reduzida ​

Answer 1

Resposta:

$x\left(x-8\right)=3x^2-4x\\\\x^2-8x=3x^2-4x\\\\x^2-8x+4x=3x^2-4x+4x\\\\x^2-4x=3x^2\\\\x^2-4x-3x^2=3x^2-3x^2\\\\-2x^2-4x=0\\\\x_{1,\:2}=\frac{-\left(-4\right)\pm \sqrt{\left(-4\right)^2-4\left(-2\right)\cdot \:0}}{2\left(-2\right)}\\\\x_{1,\:2}=\frac{-\left(-4\right)\pm \:4}{2\left(-2\right)}\\\\x_1=\frac{-\left(-4\right)+4}{2\left(-2\right)},\:x_2=\frac{-\left(-4\right)-4}{2\left(-2\right)}\\\\x=-2,\:x=0$