Question

quanto dá a conta y=x2-8x+7=0

Answer 1

Delta=b²-4.a.c 
Delta= -8²-4.1.7
Delta=64-28
Delta=36

x = – b ± √Δ ÷ 2a
x= -(-8)± √36/ 2
x=8± 6/2

x1= 14/2=>7
x2=2/2=>1