Question

Alguém poderia mim ajudar ?
2×2+11=×2+12

Answer 1

$2x^2+11= x^{2} +12\to \\\\ 2 x^{2} - x^{2} =12-11\to \\\\ x^{2} =1\to \\\\ x=+- \sqrt{1} \to \\\\ x=+-1\\\\\\\ x'=-1\\x''=1\\\\\\ S=(-1;1)$