Question

Achar as raízes das equações incompletas na forma ax2 + C=0
a) x2-49 = 0
b) 7x²-7=0
c) 2x2 - 50 = 0
d) 21 = 7x2
e) 3 (x2 - 1) = 24
f) 2x2 - 90 = 8​

Answer 1

a) x2-49 = 0 => x²=49 => x=√49 => x=±7

b) 7x²-7=0 => 7x²=7 => x²=1 => x=±1

c) 2x2 -50 =0 => 2x²=50 =>x²=25=>x=±5

d) 21 = 7x2 => x³=3 => x=±√3

e) 3 (x²-1)=24 => x²-1=8 => x²=9 =>x=±3

f) 2x2 -90=8 => 2x²=98 =>x²=49 => x=±7