Question

4x2 - 9 = 0

Answer 1

4x^(2)-9=0

Since -9 does not contain the variable to solve for, move it to the right-hand side of the equation by adding 9 to both sides.
4x^(2)=9

Divide each term in the equation by 4.
x^(2)=(9)/(4)

Take the square root of both sides of the equation to eliminate the exponent on the left-hand side.
x=+-sqrt((9)/(4))

Pull all perfect square roots out from under the radical. In this case, remove the 3 because it is a perfect square.
x=+-(3)/(2)

First, substitute in the + portion of the \ to find the first solution.
x=(3)/(2)

Next, substitute in the - portion of the \ to find the second solution.
x=-(3)/(2)

The complete solution is the result of both the + and - portions of the solution.
x=(3)/(2),-(3)/(2)