Question

X elevado ao quadrado + 8x = 9

Answer 1

x²+8x=9
x²+8x-9=0

Delta=b²-4.a.c
Delta=8²-4.1.-9
Delta=64+36
Delta=100

x=-b+-Raiz de delta/2.a
x=-8+-Raiz de 100/2.1
x=-8+-10/2

x1=-8+10/2
x1=2/2
x1=1

x2=-8-10/2
x2=-18/2
x2=-9