Question

Resolva as equações a seguir.

a) (x-7).(x+7) = 0

b) x² + 30 = 111

c) 7x² + 2x = 0

d) 3y² - 6y = 0

Answer 1

a) x*2+7x-7x-49=0
x*2-49=0
x*2=49
x=\/`49
x=7 x=-7

b) x*2+30-111=0
x*2-81=0
x*2=81
x=\/`81
x=9 x=-9

c) 7x*2+2x=0
x (7x+2)=0
x=0
7x+2=0
7x=-2
x= -2/7

d) 3y*2-6y=0
y (3y-6)=0
y=0
3y-6=0
3y=6
y=6/3
y=2