Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

3x^{2}=25
Add 25 to both sides. Anything plus zero gives itself.
x^{2}=\frac{25}{3}
Divide both sides by 3.
x=\frac{5\sqrt{3}}{3} x=-\frac{5\sqrt{3}}{3}
Take the square root of both sides of the equation.
3x^{2}-25=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 3\left(-25\right)}}{2\times 3}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 3 for a, 0 for b, and -25 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 3\left(-25\right)}}{2\times 3}
Square 0.
x=\frac{0±\sqrt{-12\left(-25\right)}}{2\times 3}
Multiply -4 times 3.
x=\frac{0±\sqrt{300}}{2\times 3}
Multiply -12 times -25.
x=\frac{0±10\sqrt{3}}{2\times 3}
Take the square root of 300.
x=\frac{0±10\sqrt{3}}{6}
Multiply 2 times 3.
x=\frac{5\sqrt{3}}{3}
Now solve the equation x=\frac{0±10\sqrt{3}}{6} when ± is plus.
x=-\frac{5\sqrt{3}}{3}
Now solve the equation x=\frac{0±10\sqrt{3}}{6} when ± is minus.
x=\frac{5\sqrt{3}}{3} x=-\frac{5\sqrt{3}}{3}
The equation is now solved.