How do you solve 4x²-12=0?

2 Answers
Mar 20, 2018

x = +- 3

Explanation:

4x^2-12=0

=>4(x^2-3)=0

=>x^2-3 = 0

=>x^2 = 3

=>x = +- 3

x = +-sqrt3

Explanation:

Step 1:
Put all terms with x on one side of the equation and all terms without x on the other side of the equation.
4x^2 - 12 = 0
4x^2 = 12

Step 2:
Divide the equation (both sides) by largest common coefficient of 4.
x^2 = 3

Step 3:
Square the equation (both sides) to obtain x on one side as the subject of the equation (what you want to find).
Because 3 cannot be square-rooted to a whole answer, leave your answer in the root form.
x = +-sqrt3

Note:
In Step 2, you divided the equation by the coefficient 4. Take note that you cannot divide an equation by what you are finding (which in this case is x), especially if you have a quadratic equation (an equation with x^n where n is any real number).
In Step 3, remember to always add the +- after square-rooting unless you are doing an equation for real-world values (where there are no negative answers).