Question

X ao quadrado + X (2X-15)=0

Answer 1

x² + x (2x - 15) = 0
x² + 2x² - 15x = 0
3x² - 15x = 0

Δ = (-15)² - 4 .3.0 
Δ = 225 - 0 
Δ = 225

$x= \frac{-(-15)+- \sqrt{225} }{2.3} =x= \frac{+15+-15}{6} \\ \\ x'= \frac{+15+15}{6}= 5 \\ \\ x''= \frac{+15-15}{6} =0$

S{5,0}