Question

x ao quadrado menos 6× menos 7 igual a 0

Answer 1

x^2-6x-7=0
▲=b^2-4ac
▲=(-6)^2-4.1.(-7)
▲=36+28
▲=64
x=-b-/+ raiz de delta /2a
x=-(-6)-8/2.1
x=6-8/2
x=-2/2
x=-1
x=-(-6)+8/2.1
x=6+8/2
x=14/2
x=7