Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

x\left(1+5x\right)=\left(x+1\right)\left(2+x\right)
Variable x cannot be equal to any of the values -1,0 since division by zero is not defined. Multiply both sides of the equation by x\left(x+1\right), the least common multiple of x+1,x.
x+5x^{2}=\left(x+1\right)\left(2+x\right)
Use the distributive property to multiply x by 1+5x.
x+5x^{2}=3x+x^{2}+2
Use the distributive property to multiply x+1 by 2+x and combine like terms.
x+5x^{2}-3x=x^{2}+2
Subtract 3x from both sides.
-2x+5x^{2}=x^{2}+2
Combine x and -3x to get -2x.
-2x+5x^{2}-x^{2}=2
Subtract x^{2} from both sides.
-2x+4x^{2}=2
Combine 5x^{2} and -x^{2} to get 4x^{2}.
-2x+4x^{2}-2=0
Subtract 2 from both sides.
4x^{2}-2x-2=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{-\left(-2\right)±\sqrt{\left(-2\right)^{2}-4\times 4\left(-2\right)}}{2\times 4}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 4 for a, -2 for b, and -2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-2\right)±\sqrt{4-4\times 4\left(-2\right)}}{2\times 4}
Square -2.
x=\frac{-\left(-2\right)±\sqrt{4-16\left(-2\right)}}{2\times 4}
Multiply -4 times 4.
x=\frac{-\left(-2\right)±\sqrt{4+32}}{2\times 4}
Multiply -16 times -2.
x=\frac{-\left(-2\right)±\sqrt{36}}{2\times 4}
Add 4 to 32.
x=\frac{-\left(-2\right)±6}{2\times 4}
Take the square root of 36.
x=\frac{2±6}{2\times 4}
The opposite of -2 is 2.
x=\frac{2±6}{8}
Multiply 2 times 4.
x=\frac{8}{8}
Now solve the equation x=\frac{2±6}{8} when ± is plus. Add 2 to 6.
x=1
Divide 8 by 8.
x=-\frac{4}{8}
Now solve the equation x=\frac{2±6}{8} when ± is minus. Subtract 6 from 2.
x=-\frac{1}{2}
Reduce the fraction \frac{-4}{8} to lowest terms by extracting and canceling out 4.
x=1 x=-\frac{1}{2}
The equation is now solved.
x\left(1+5x\right)=\left(x+1\right)\left(2+x\right)
Variable x cannot be equal to any of the values -1,0 since division by zero is not defined. Multiply both sides of the equation by x\left(x+1\right), the least common multiple of x+1,x.
x+5x^{2}=\left(x+1\right)\left(2+x\right)
Use the distributive property to multiply x by 1+5x.
x+5x^{2}=3x+x^{2}+2
Use the distributive property to multiply x+1 by 2+x and combine like terms.
x+5x^{2}-3x=x^{2}+2
Subtract 3x from both sides.
-2x+5x^{2}=x^{2}+2
Combine x and -3x to get -2x.
-2x+5x^{2}-x^{2}=2
Subtract x^{2} from both sides.
-2x+4x^{2}=2
Combine 5x^{2} and -x^{2} to get 4x^{2}.
4x^{2}-2x=2
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{4x^{2}-2x}{4}=\frac{2}{4}
Divide both sides by 4.
x^{2}+\left(-\frac{2}{4}\right)x=\frac{2}{4}
Dividing by 4 undoes the multiplication by 4.
x^{2}-\frac{1}{2}x=\frac{2}{4}
Reduce the fraction \frac{-2}{4} to lowest terms by extracting and canceling out 2.
x^{2}-\frac{1}{2}x=\frac{1}{2}
Reduce the fraction \frac{2}{4} to lowest terms by extracting and canceling out 2.
x^{2}-\frac{1}{2}x+\left(-\frac{1}{4}\right)^{2}=\frac{1}{2}+\left(-\frac{1}{4}\right)^{2}
Divide -\frac{1}{2}, the coefficient of the x term, by 2 to get -\frac{1}{4}. Then add the square of -\frac{1}{4} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{1}{2}x+\frac{1}{16}=\frac{1}{2}+\frac{1}{16}
Square -\frac{1}{4} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{1}{2}x+\frac{1}{16}=\frac{9}{16}
Add \frac{1}{2} to \frac{1}{16} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{1}{4}\right)^{2}=\frac{9}{16}
Factor x^{2}-\frac{1}{2}x+\frac{1}{16}. 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}{4}\right)^{2}}=\sqrt{\frac{9}{16}}
Take the square root of both sides of the equation.
x-\frac{1}{4}=\frac{3}{4} x-\frac{1}{4}=-\frac{3}{4}
Simplify.
x=1 x=-\frac{1}{2}
Add \frac{1}{4} to both sides of the equation.