Question

Найти корни x²+3x-28

Answer 1

D=$b^{2}$-4ac=9-4×1×(-28)=9+112=121

x1=$\frac{-3+\sqrt{121}} {2}$=$\frac{8}{2}$=4

x2=$\frac{-3-\sqrt{121}} {2}$=$\frac{-14}{2}$=-7