Question

Qual é o resultado de:
4x^2-3x-9=0

Answer 1

$\Large\boxed{\begin{array}{l}\sf 4x^2-3x-9=0\\\sf a=4\quad b=-3\quad c=-9\\\sf\Delta=b^2-4\cdot a\cdot c\\\sf\Delta=(-3)^2-4\cdot 4\cdot(-9)\\\sf \Delta=9+ 144\\\sf\Delta= 153\\\sf x=\dfrac{-b\pm\sqrt\Delta}{2\cdot a}\\\\\sf x=\dfrac{-(-3)\pm\sqrt{153}}{2\cdot4}\\\\\sf x=\dfrac{3\pm 3\sqrt{17}}{8}\\\\\sf S=\left\{\dfrac{3-3\sqrt{17}}{8};\dfrac{3+3\sqrt{17}}{8}\right\}\end{array}}$