Question

X elevado ao quadrado menos 8x + 15 = 0

Answer 1

X²-8x+15=0
a=1 b=-8 c=15

∆=b²-4.a.c
∆=64-4.1.15
∆=64-60
∆=4
√∆=2

x=-b±√∆/2a

x=8±2/2

x'=8+2/2
x'=5

x"=8-2/2
x"=3

S: X'=5 e X"=3