Question

4x в квадрате -7x-15=0

Answer 1

$D=b^2-4ac=(-7)^2-4*4*(-15)=49+240=289 sqrt{D}=17 x_{1}= frac{7+17}{2*4}= frac{24}{8}=3 x_{2}= frac{7-17}{2*4}= frac{-10}{8}= -1,25 Otvet:3;-1,25.$