Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

\left(3x-6\right)x-5\times 2=15\times 4
Variable x cannot be equal to 2 since division by zero is not defined. Multiply both sides of the equation by 15\left(x-2\right), the least common multiple of 5,3x-6,x-2.
3x^{2}-6x-5\times 2=15\times 4
Use the distributive property to multiply 3x-6 by x.
3x^{2}-6x-10=15\times 4
Multiply -5 and 2 to get -10.
3x^{2}-6x-10=60
Multiply 15 and 4 to get 60.
3x^{2}-6x-10-60=0
Subtract 60 from both sides.
3x^{2}-6x-70=0
Subtract 60 from -10 to get -70.
x=\frac{-\left(-6\right)±\sqrt{\left(-6\right)^{2}-4\times 3\left(-70\right)}}{2\times 3}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 3 for a, -6 for b, and -70 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-6\right)±\sqrt{36-4\times 3\left(-70\right)}}{2\times 3}
Square -6.
x=\frac{-\left(-6\right)±\sqrt{36-12\left(-70\right)}}{2\times 3}
Multiply -4 times 3.
x=\frac{-\left(-6\right)±\sqrt{36+840}}{2\times 3}
Multiply -12 times -70.
x=\frac{-\left(-6\right)±\sqrt{876}}{2\times 3}
Add 36 to 840.
x=\frac{-\left(-6\right)±2\sqrt{219}}{2\times 3}
Take the square root of 876.
x=\frac{6±2\sqrt{219}}{2\times 3}
The opposite of -6 is 6.
x=\frac{6±2\sqrt{219}}{6}
Multiply 2 times 3.
x=\frac{2\sqrt{219}+6}{6}
Now solve the equation x=\frac{6±2\sqrt{219}}{6} when ± is plus. Add 6 to 2\sqrt{219}.
x=\frac{\sqrt{219}}{3}+1
Divide 6+2\sqrt{219} by 6.
x=\frac{6-2\sqrt{219}}{6}
Now solve the equation x=\frac{6±2\sqrt{219}}{6} when ± is minus. Subtract 2\sqrt{219} from 6.
x=-\frac{\sqrt{219}}{3}+1
Divide 6-2\sqrt{219} by 6.
x=\frac{\sqrt{219}}{3}+1 x=-\frac{\sqrt{219}}{3}+1
The equation is now solved.
\left(3x-6\right)x-5\times 2=15\times 4
Variable x cannot be equal to 2 since division by zero is not defined. Multiply both sides of the equation by 15\left(x-2\right), the least common multiple of 5,3x-6,x-2.
3x^{2}-6x-5\times 2=15\times 4
Use the distributive property to multiply 3x-6 by x.
3x^{2}-6x-10=15\times 4
Multiply -5 and 2 to get -10.
3x^{2}-6x-10=60
Multiply 15 and 4 to get 60.
3x^{2}-6x=60+10
Add 10 to both sides.
3x^{2}-6x=70
Add 60 and 10 to get 70.
\frac{3x^{2}-6x}{3}=\frac{70}{3}
Divide both sides by 3.
x^{2}+\left(-\frac{6}{3}\right)x=\frac{70}{3}
Dividing by 3 undoes the multiplication by 3.
x^{2}-2x=\frac{70}{3}
Divide -6 by 3.
x^{2}-2x+1=\frac{70}{3}+1
Divide -2, the coefficient of the x term, by 2 to get -1. Then add the square of -1 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-2x+1=\frac{73}{3}
Add \frac{70}{3} to 1.
\left(x-1\right)^{2}=\frac{73}{3}
Factor x^{2}-2x+1. 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-1\right)^{2}}=\sqrt{\frac{73}{3}}
Take the square root of both sides of the equation.
x-1=\frac{\sqrt{219}}{3} x-1=-\frac{\sqrt{219}}{3}
Simplify.
x=\frac{\sqrt{219}}{3}+1 x=-\frac{\sqrt{219}}{3}+1
Add 1 to both sides of the equation.