Question

Quanto é?

a)2x²-72=0. c)-64+4x²=0.

b)x²=99-10x². d)0,15x²=0,6.

Answer 1

a) 2x²-72=0
2x²=72
x²=72/2
x²=36
x=±√36
x=±6

b)x²=99-10x²
x²+10x²=99
11x²=99
x²=99/11
x²=9
x=±√9
x=±3

c) -64+4x²=0
4x²=64
x²=64/4
x²=16
x=±√16
x=±4

d)0,15x²=0,6
x²=0,6/0,15
x²=4
x=±√4
x=±2