Question

2. Resolva as questões do tipo a.x²+c=0,isolando o X.

a) 6.x²-150=0
b) 4.x²+64=0
c) 12.x²-3=0
d) 49.x²-1=0

Answer 1

a )

$6x^2-150=0\\6x^2=150\\ \\x^2= \frac{150}{6} \\ \\x^2=25\\ \\x=\pm \sqrt{25} \\ \\x=\pm5$

b )

$4x^2+64=0~~\div 4\\ \\x^2+16=0\\ \\x^2=-16\\ \\x=\pm \sqrt{-16} \\ \\x=\pm4i$

c )

$12x^2-3=0~~~\div3\\ \\4x^2-1=0\\ \\4x^2=1\\ \\x^2= \frac{1}{4} \\ \\x=\pm \sqrt{ \frac{1}{4} } \\ \\x=\pm \frac{1}{2}$

d )

$49x^2-1=0\\ \\49x^2=1\\ \\x^2= \frac{1}{49} \\ \\x=\pm \sqrt{ \frac{1}{49} } \\ \\x=\pm \frac{1}{7}$