Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

x^{2}-36=0
Divide both sides by 4.
\left(x-6\right)\left(x+6\right)=0
Consider x^{2}-36. Rewrite x^{2}-36 as x^{2}-6^{2}. The difference of squares can be factored using the rule: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).
x=6 x=-6
To find equation solutions, solve x-6=0 and x+6=0.
4x^{2}=144
Add 144 to both sides. Anything plus zero gives itself.
x^{2}=\frac{144}{4}
Divide both sides by 4.
x^{2}=36
Divide 144 by 4 to get 36.
x=6 x=-6
Take the square root of both sides of the equation.
4x^{2}-144=0
Quadratic equations like this one, with an x^{2} term but no x term, can still be solved using the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, once they are put in standard form: ax^{2}+bx+c=0.
x=\frac{0±\sqrt{0^{2}-4\times 4\left(-144\right)}}{2\times 4}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 4 for a, 0 for b, and -144 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 4\left(-144\right)}}{2\times 4}
Square 0.
x=\frac{0±\sqrt{-16\left(-144\right)}}{2\times 4}
Multiply -4 times 4.
x=\frac{0±\sqrt{2304}}{2\times 4}
Multiply -16 times -144.
x=\frac{0±48}{2\times 4}
Take the square root of 2304.
x=\frac{0±48}{8}
Multiply 2 times 4.
x=6
Now solve the equation x=\frac{0±48}{8} when ± is plus. Divide 48 by 8.
x=-6
Now solve the equation x=\frac{0±48}{8} when ± is minus. Divide -48 by 8.
x=6 x=-6
The equation is now solved.