Solve for x
x=\frac{1}{4}=0.25
x = \frac{3}{2} = 1\frac{1}{2} = 1.5
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9x^{2}-12x+4=\left(x+1\right)^{2}
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(3x-2\right)^{2}.
9x^{2}-12x+4=x^{2}+2x+1
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+1\right)^{2}.
9x^{2}-12x+4-x^{2}=2x+1
Subtract x^{2} from both sides.
8x^{2}-12x+4=2x+1
Combine 9x^{2} and -x^{2} to get 8x^{2}.
8x^{2}-12x+4-2x=1
Subtract 2x from both sides.
8x^{2}-14x+4=1
Combine -12x and -2x to get -14x.
8x^{2}-14x+4-1=0
Subtract 1 from both sides.
8x^{2}-14x+3=0
Subtract 1 from 4 to get 3.
a+b=-14 ab=8\times 3=24
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 8x^{2}+ax+bx+3. To find a and b, set up a system to be solved.
-1,-24 -2,-12 -3,-8 -4,-6
Since ab is positive, a and b have the same sign. Since a+b is negative, a and b are both negative. List all such integer pairs that give product 24.
-1-24=-25 -2-12=-14 -3-8=-11 -4-6=-10
Calculate the sum for each pair.
a=-12 b=-2
The solution is the pair that gives sum -14.
\left(8x^{2}-12x\right)+\left(-2x+3\right)
Rewrite 8x^{2}-14x+3 as \left(8x^{2}-12x\right)+\left(-2x+3\right).
4x\left(2x-3\right)-\left(2x-3\right)
Factor out 4x in the first and -1 in the second group.
\left(2x-3\right)\left(4x-1\right)
Factor out common term 2x-3 by using distributive property.
x=\frac{3}{2} x=\frac{1}{4}
To find equation solutions, solve 2x-3=0 and 4x-1=0.
9x^{2}-12x+4=\left(x+1\right)^{2}
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(3x-2\right)^{2}.
9x^{2}-12x+4=x^{2}+2x+1
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+1\right)^{2}.
9x^{2}-12x+4-x^{2}=2x+1
Subtract x^{2} from both sides.
8x^{2}-12x+4=2x+1
Combine 9x^{2} and -x^{2} to get 8x^{2}.
8x^{2}-12x+4-2x=1
Subtract 2x from both sides.
8x^{2}-14x+4=1
Combine -12x and -2x to get -14x.
8x^{2}-14x+4-1=0
Subtract 1 from both sides.
8x^{2}-14x+3=0
Subtract 1 from 4 to get 3.
x=\frac{-\left(-14\right)±\sqrt{\left(-14\right)^{2}-4\times 8\times 3}}{2\times 8}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 8 for a, -14 for b, and 3 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-14\right)±\sqrt{196-4\times 8\times 3}}{2\times 8}
Square -14.
x=\frac{-\left(-14\right)±\sqrt{196-32\times 3}}{2\times 8}
Multiply -4 times 8.
x=\frac{-\left(-14\right)±\sqrt{196-96}}{2\times 8}
Multiply -32 times 3.
x=\frac{-\left(-14\right)±\sqrt{100}}{2\times 8}
Add 196 to -96.
x=\frac{-\left(-14\right)±10}{2\times 8}
Take the square root of 100.
x=\frac{14±10}{2\times 8}
The opposite of -14 is 14.
x=\frac{14±10}{16}
Multiply 2 times 8.
x=\frac{24}{16}
Now solve the equation x=\frac{14±10}{16} when ± is plus. Add 14 to 10.
x=\frac{3}{2}
Reduce the fraction \frac{24}{16} to lowest terms by extracting and canceling out 8.
x=\frac{4}{16}
Now solve the equation x=\frac{14±10}{16} when ± is minus. Subtract 10 from 14.
x=\frac{1}{4}
Reduce the fraction \frac{4}{16} to lowest terms by extracting and canceling out 4.
x=\frac{3}{2} x=\frac{1}{4}
The equation is now solved.
9x^{2}-12x+4=\left(x+1\right)^{2}
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(3x-2\right)^{2}.
9x^{2}-12x+4=x^{2}+2x+1
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+1\right)^{2}.
9x^{2}-12x+4-x^{2}=2x+1
Subtract x^{2} from both sides.
8x^{2}-12x+4=2x+1
Combine 9x^{2} and -x^{2} to get 8x^{2}.
8x^{2}-12x+4-2x=1
Subtract 2x from both sides.
8x^{2}-14x+4=1
Combine -12x and -2x to get -14x.
8x^{2}-14x=1-4
Subtract 4 from both sides.
8x^{2}-14x=-3
Subtract 4 from 1 to get -3.
\frac{8x^{2}-14x}{8}=-\frac{3}{8}
Divide both sides by 8.
x^{2}+\left(-\frac{14}{8}\right)x=-\frac{3}{8}
Dividing by 8 undoes the multiplication by 8.
x^{2}-\frac{7}{4}x=-\frac{3}{8}
Reduce the fraction \frac{-14}{8} to lowest terms by extracting and canceling out 2.
x^{2}-\frac{7}{4}x+\left(-\frac{7}{8}\right)^{2}=-\frac{3}{8}+\left(-\frac{7}{8}\right)^{2}
Divide -\frac{7}{4}, the coefficient of the x term, by 2 to get -\frac{7}{8}. Then add the square of -\frac{7}{8} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{7}{4}x+\frac{49}{64}=-\frac{3}{8}+\frac{49}{64}
Square -\frac{7}{8} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{7}{4}x+\frac{49}{64}=\frac{25}{64}
Add -\frac{3}{8} to \frac{49}{64} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{7}{8}\right)^{2}=\frac{25}{64}
Factor x^{2}-\frac{7}{4}x+\frac{49}{64}. 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{7}{8}\right)^{2}}=\sqrt{\frac{25}{64}}
Take the square root of both sides of the equation.
x-\frac{7}{8}=\frac{5}{8} x-\frac{7}{8}=-\frac{5}{8}
Simplify.
x=\frac{3}{2} x=\frac{1}{4}
Add \frac{7}{8} to both sides of the equation.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}