Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

3\left(4x+6\right)=\left(6x+2\right)\times 2x
Variable x cannot be equal to -\frac{1}{3} since division by zero is not defined. Multiply both sides of the equation by 12\left(3x+1\right), the least common multiple of 12x+4,6.
12x+18=\left(6x+2\right)\times 2x
Use the distributive property to multiply 3 by 4x+6.
12x+18=\left(12x+4\right)x
Use the distributive property to multiply 6x+2 by 2.
12x+18=12x^{2}+4x
Use the distributive property to multiply 12x+4 by x.
12x+18-12x^{2}=4x
Subtract 12x^{2} from both sides.
12x+18-12x^{2}-4x=0
Subtract 4x from both sides.
8x+18-12x^{2}=0
Combine 12x and -4x to get 8x.
-12x^{2}+8x+18=0
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
x=\frac{-8±\sqrt{8^{2}-4\left(-12\right)\times 18}}{2\left(-12\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -12 for a, 8 for b, and 18 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-8±\sqrt{64-4\left(-12\right)\times 18}}{2\left(-12\right)}
Square 8.
x=\frac{-8±\sqrt{64+48\times 18}}{2\left(-12\right)}
Multiply -4 times -12.
x=\frac{-8±\sqrt{64+864}}{2\left(-12\right)}
Multiply 48 times 18.
x=\frac{-8±\sqrt{928}}{2\left(-12\right)}
Add 64 to 864.
x=\frac{-8±4\sqrt{58}}{2\left(-12\right)}
Take the square root of 928.
x=\frac{-8±4\sqrt{58}}{-24}
Multiply 2 times -12.
x=\frac{4\sqrt{58}-8}{-24}
Now solve the equation x=\frac{-8±4\sqrt{58}}{-24} when ± is plus. Add -8 to 4\sqrt{58}.
x=-\frac{\sqrt{58}}{6}+\frac{1}{3}
Divide -8+4\sqrt{58} by -24.
x=\frac{-4\sqrt{58}-8}{-24}
Now solve the equation x=\frac{-8±4\sqrt{58}}{-24} when ± is minus. Subtract 4\sqrt{58} from -8.
x=\frac{\sqrt{58}}{6}+\frac{1}{3}
Divide -8-4\sqrt{58} by -24.
x=-\frac{\sqrt{58}}{6}+\frac{1}{3} x=\frac{\sqrt{58}}{6}+\frac{1}{3}
The equation is now solved.
3\left(4x+6\right)=\left(6x+2\right)\times 2x
Variable x cannot be equal to -\frac{1}{3} since division by zero is not defined. Multiply both sides of the equation by 12\left(3x+1\right), the least common multiple of 12x+4,6.
12x+18=\left(6x+2\right)\times 2x
Use the distributive property to multiply 3 by 4x+6.
12x+18=\left(12x+4\right)x
Use the distributive property to multiply 6x+2 by 2.
12x+18=12x^{2}+4x
Use the distributive property to multiply 12x+4 by x.
12x+18-12x^{2}=4x
Subtract 12x^{2} from both sides.
12x+18-12x^{2}-4x=0
Subtract 4x from both sides.
8x+18-12x^{2}=0
Combine 12x and -4x to get 8x.
8x-12x^{2}=-18
Subtract 18 from both sides. Anything subtracted from zero gives its negation.
-12x^{2}+8x=-18
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
\frac{-12x^{2}+8x}{-12}=-\frac{18}{-12}
Divide both sides by -12.
x^{2}+\frac{8}{-12}x=-\frac{18}{-12}
Dividing by -12 undoes the multiplication by -12.
x^{2}-\frac{2}{3}x=-\frac{18}{-12}
Reduce the fraction \frac{8}{-12} to lowest terms by extracting and canceling out 4.
x^{2}-\frac{2}{3}x=\frac{3}{2}
Reduce the fraction \frac{-18}{-12} to lowest terms by extracting and canceling out 6.
x^{2}-\frac{2}{3}x+\left(-\frac{1}{3}\right)^{2}=\frac{3}{2}+\left(-\frac{1}{3}\right)^{2}
Divide -\frac{2}{3}, the coefficient of the x term, by 2 to get -\frac{1}{3}. Then add the square of -\frac{1}{3} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{2}{3}x+\frac{1}{9}=\frac{3}{2}+\frac{1}{9}
Square -\frac{1}{3} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{2}{3}x+\frac{1}{9}=\frac{29}{18}
Add \frac{3}{2} to \frac{1}{9} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{1}{3}\right)^{2}=\frac{29}{18}
Factor x^{2}-\frac{2}{3}x+\frac{1}{9}. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(x-\frac{1}{3}\right)^{2}}=\sqrt{\frac{29}{18}}
Take the square root of both sides of the equation.
x-\frac{1}{3}=\frac{\sqrt{58}}{6} x-\frac{1}{3}=-\frac{\sqrt{58}}{6}
Simplify.
x=\frac{\sqrt{58}}{6}+\frac{1}{3} x=-\frac{\sqrt{58}}{6}+\frac{1}{3}
Add \frac{1}{3} to both sides of the equation.