Solve for x
x=-3
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4\left(\left(\frac{3}{4}-1\right)x^{2}-\frac{2\times 3}{4}x\right)+3-12=0
Multiply both sides of the equation by 4.
4\left(-\frac{1}{4}x^{2}-\frac{2\times 3}{4}x\right)+3-12=0
Subtract 1 from \frac{3}{4} to get -\frac{1}{4}.
4\left(-\frac{1}{4}x^{2}-\frac{6}{4}x\right)+3-12=0
Multiply 2 and 3 to get 6.
4\left(-\frac{1}{4}x^{2}-\frac{3}{2}x\right)+3-12=0
Reduce the fraction \frac{6}{4} to lowest terms by extracting and canceling out 2.
-x^{2}-6x+3-12=0
Use the distributive property to multiply 4 by -\frac{1}{4}x^{2}-\frac{3}{2}x.
-x^{2}-6x-9=0
Subtract 12 from 3 to get -9.
a+b=-6 ab=-\left(-9\right)=9
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as -x^{2}+ax+bx-9. To find a and b, set up a system to be solved.
-1,-9 -3,-3
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 9.
-1-9=-10 -3-3=-6
Calculate the sum for each pair.
a=-3 b=-3
The solution is the pair that gives sum -6.
\left(-x^{2}-3x\right)+\left(-3x-9\right)
Rewrite -x^{2}-6x-9 as \left(-x^{2}-3x\right)+\left(-3x-9\right).
x\left(-x-3\right)+3\left(-x-3\right)
Factor out x in the first and 3 in the second group.
\left(-x-3\right)\left(x+3\right)
Factor out common term -x-3 by using distributive property.
x=-3 x=-3
To find equation solutions, solve -x-3=0 and x+3=0.
4\left(\left(\frac{3}{4}-1\right)x^{2}-\frac{2\times 3}{4}x\right)+3-12=0
Multiply both sides of the equation by 4.
4\left(-\frac{1}{4}x^{2}-\frac{2\times 3}{4}x\right)+3-12=0
Subtract 1 from \frac{3}{4} to get -\frac{1}{4}.
4\left(-\frac{1}{4}x^{2}-\frac{6}{4}x\right)+3-12=0
Multiply 2 and 3 to get 6.
4\left(-\frac{1}{4}x^{2}-\frac{3}{2}x\right)+3-12=0
Reduce the fraction \frac{6}{4} to lowest terms by extracting and canceling out 2.
-x^{2}-6x+3-12=0
Use the distributive property to multiply 4 by -\frac{1}{4}x^{2}-\frac{3}{2}x.
-x^{2}-6x-9=0
Subtract 12 from 3 to get -9.
x=\frac{-\left(-6\right)±\sqrt{\left(-6\right)^{2}-4\left(-1\right)\left(-9\right)}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, -6 for b, and -9 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-6\right)±\sqrt{36-4\left(-1\right)\left(-9\right)}}{2\left(-1\right)}
Square -6.
x=\frac{-\left(-6\right)±\sqrt{36+4\left(-9\right)}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-\left(-6\right)±\sqrt{36-36}}{2\left(-1\right)}
Multiply 4 times -9.
x=\frac{-\left(-6\right)±\sqrt{0}}{2\left(-1\right)}
Add 36 to -36.
x=-\frac{-6}{2\left(-1\right)}
Take the square root of 0.
x=\frac{6}{2\left(-1\right)}
The opposite of -6 is 6.
x=\frac{6}{-2}
Multiply 2 times -1.
x=-3
Divide 6 by -2.
4\left(\left(\frac{3}{4}-1\right)x^{2}-\frac{2\times 3}{4}x\right)+3-12=0
Multiply both sides of the equation by 4.
4\left(-\frac{1}{4}x^{2}-\frac{2\times 3}{4}x\right)+3-12=0
Subtract 1 from \frac{3}{4} to get -\frac{1}{4}.
4\left(-\frac{1}{4}x^{2}-\frac{6}{4}x\right)+3-12=0
Multiply 2 and 3 to get 6.
4\left(-\frac{1}{4}x^{2}-\frac{3}{2}x\right)+3-12=0
Reduce the fraction \frac{6}{4} to lowest terms by extracting and canceling out 2.
-x^{2}-6x+3-12=0
Use the distributive property to multiply 4 by -\frac{1}{4}x^{2}-\frac{3}{2}x.
-x^{2}-6x-9=0
Subtract 12 from 3 to get -9.
-x^{2}-6x=9
Add 9 to both sides. Anything plus zero gives itself.
\frac{-x^{2}-6x}{-1}=\frac{9}{-1}
Divide both sides by -1.
x^{2}+\left(-\frac{6}{-1}\right)x=\frac{9}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}+6x=\frac{9}{-1}
Divide -6 by -1.
x^{2}+6x=-9
Divide 9 by -1.
x^{2}+6x+3^{2}=-9+3^{2}
Divide 6, the coefficient of the x term, by 2 to get 3. Then add the square of 3 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+6x+9=-9+9
Square 3.
x^{2}+6x+9=0
Add -9 to 9.
\left(x+3\right)^{2}=0
Factor x^{2}+6x+9. 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+3\right)^{2}}=\sqrt{0}
Take the square root of both sides of the equation.
x+3=0 x+3=0
Simplify.
x=-3 x=-3
Subtract 3 from both sides of the equation.
x=-3
The equation is now solved. Solutions are the same.
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}