Question

Transforme na forma geral ax² + bx + c = 0, e resolva a equação (x + 2).(x - 2) + 7x = - 10, usando a fórmula de Bháskara.​.​

Answer 1

$\Large\boxed{\begin{array}{l}\sf (x+2)\cdot (x-2)+7x=-10\\\sf x^2-4+7x+10=0\\\sf x^2+7x+6=0\\\sf\Delta=b^2-4ac\\\sf\Delta=7^2-4\cdot1\cdot6\\\sf\Delta=49-24\\\sf\Delta=25\\\sf x=\dfrac{-b\pm\sqrt{\Delta}}{2a}\\\\\sf x=\dfrac{-7\pm\sqrt{25}}{2\cdot1}\\\\\sf x=\dfrac{-7\pm5}{2}\begin{cases}\sf x_1=\dfrac{-7+5}{2}=-\dfrac{2}{2}=-1\\\\\sf x_2=\dfrac{-7-5}{2}=-\dfrac{12}{2}=-6\end{cases}\\\\\sf S=\{-6,-1\}\end{array}}$