Question

-X²13x-40=0 alguém pode mim ajudar pfvr?

Answer 1

$x= \frac{-b \frac{+}{-} \sqrt{ b^{2}-4ac } }{2 a} \\ x= \frac{-(-13) \frac{+}{-} \sqrt{ -13^{2} -4*(-1)*(-40)} }{2*(-1)} \\ x= \frac{13 \frac{+}{-} \sqrt{169-160} }{-2} \\ x= \frac{13 \frac{+}{-} \sqrt{9} }{-2} \\ x= \frac{13 \frac{+}{-}3 }{-2} \\ x^{'} = \frac{13+3}{-2} = \frac{16}{-2} = -8 \\ x^{''} = \frac{13-3}{-2} = \frac{10}{-2} =-5$