Answer:
[tex]x=-7, \\x=7[/tex]
Step-by-step explanation:
Given [tex]3x^2-7=140[/tex], our goal is to isolate [tex]x[/tex].
Start by adding 7 to both sides:
[tex]3x^2=147[/tex]
Divide both sides by 3:
[tex]x^2=49[/tex]
Take the square root of both sides:
[tex]x=\pm \sqrt{49}=\pm 7[/tex]
Recall that [tex]7^2=(-7)^2=49[/tex].
Thus, we have:
[tex]x=-7, \\x=7[/tex]
