Question

calcule o valor das equacoes a) x²+8x+7=0 b) x²+x+5=0 c) x²-7x=0 d) x²-64=0 e) x²-8x+16=0

Answer 1

a) ∆=(8²)-4*a*c
∆=64-4*1*7
∆=64-28
∆=36

x=-8±6/2
x'=-2/2=-1
x"=-14/2=-7