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5x^{2}+17x-12x=0
Subtract 12x from both sides.
5x^{2}+5x=0
Combine 17x and -12x to get 5x.
x=\frac{-5±\sqrt{5^{2}}}{2\times 5}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 5 for a, 5 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-5±5}{2\times 5}
Take the square root of 5^{2}.
x=\frac{-5±5}{10}
Multiply 2 times 5.
x=\frac{0}{10}
Now solve the equation x=\frac{-5±5}{10} when ± is plus. Add -5 to 5.
x=0
Divide 0 by 10.
x=-\frac{10}{10}
Now solve the equation x=\frac{-5±5}{10} when ± is minus. Subtract 5 from -5.
x=-1
Divide -10 by 10.
x=0 x=-1
The equation is now solved.
5x^{2}+17x-12x=0
Subtract 12x from both sides.
5x^{2}+5x=0
Combine 17x and -12x to get 5x.
\frac{5x^{2}+5x}{5}=\frac{0}{5}
Divide both sides by 5.
x^{2}+\frac{5}{5}x=\frac{0}{5}
Dividing by 5 undoes the multiplication by 5.
x^{2}+x=\frac{0}{5}
Divide 5 by 5.
x^{2}+x=0
Divide 0 by 5.
x^{2}+x+\left(\frac{1}{2}\right)^{2}=\left(\frac{1}{2}\right)^{2}
Divide 1, the coefficient of the x term, by 2 to get \frac{1}{2}. Then add the square of \frac{1}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+x+\frac{1}{4}=\frac{1}{4}
Square \frac{1}{2} by squaring both the numerator and the denominator of the fraction.
\left(x+\frac{1}{2}\right)^{2}=\frac{1}{4}
Factor x^{2}+x+\frac{1}{4}. 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}{2}\right)^{2}}=\sqrt{\frac{1}{4}}
Take the square root of both sides of the equation.
x+\frac{1}{2}=\frac{1}{2} x+\frac{1}{2}=-\frac{1}{2}
Simplify.
x=0 x=-1
Subtract \frac{1}{2} from both sides of the equation.