Question

resolva a expressao numerica; (2x + 3)ao quadrado - (x-2) ao quadrado

Answer 1

(2x + 3)² - (x - 2)² = 0
(2x + 3) * (2x + 3) - (x - 2) * (x - 2) = 0
4x² + 6x + 6x + 9 - x + 2 * (x - 2) = 0
4x² + 12x + 9 - x² + 2x + 2x - 4 = 0
3x² + 16x + 5 = 0
Δ = 16² - 4 * 3 * 5
Δ = 256 - 60
Δ = 196

$x=\frac{-16\pm \sqrt{196}}{2\cdot 3}\to x=\frac{-16\pm 14}{6}\\ \\ x'=-\frac{2}{6}\to \boxed{x'=-\frac{1}{3}}\\ \\ x''=-\frac{30}{6}\to \boxed{x''=-5}\\ \\ S\{(-\frac{1}{3},-5)\}$

Espero ter ajudado (: