Solve for x
x = \frac{3}{2} = 1\frac{1}{2} = 1.5
x = -\frac{3}{2} = -1\frac{1}{2} = -1.5
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x^{2}-\frac{9}{4}=0
Subtract \frac{9}{4} from both sides.
4x^{2}-9=0
Multiply both sides by 4.
\left(2x-3\right)\left(2x+3\right)=0
Consider 4x^{2}-9. Rewrite 4x^{2}-9 as \left(2x\right)^{2}-3^{2}. The difference of squares can be factored using the rule: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).
x=\frac{3}{2} x=-\frac{3}{2}
To find equation solutions, solve 2x-3=0 and 2x+3=0.
x=\frac{3}{2} x=-\frac{3}{2}
Take the square root of both sides of the equation.
x^{2}-\frac{9}{4}=0
Subtract \frac{9}{4} from both sides.
x=\frac{0±\sqrt{0^{2}-4\left(-\frac{9}{4}\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -\frac{9}{4} for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-\frac{9}{4}\right)}}{2}
Square 0.
x=\frac{0±\sqrt{9}}{2}
Multiply -4 times -\frac{9}{4}.
x=\frac{0±3}{2}
Take the square root of 9.
x=\frac{3}{2}
Now solve the equation x=\frac{0±3}{2} when ± is plus. Divide 3 by 2.
x=-\frac{3}{2}
Now solve the equation x=\frac{0±3}{2} when ± is minus. Divide -3 by 2.
x=\frac{3}{2} x=-\frac{3}{2}
The equation is now solved.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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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}