Solve for a
a=-x\left(x+1\right)
x\neq -\frac{1}{2}
Solve for x (complex solution)
x=\frac{\sqrt{1-4a}-1}{2}
x=\frac{-\sqrt{1-4a}-1}{2}\text{, }a\neq \frac{1}{4}
Solve for x
x=\frac{\sqrt{1-4a}-1}{2}
x=\frac{-\sqrt{1-4a}-1}{2}\text{, }a<\frac{1}{4}
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x\left(2x+1\right)=x^{2}-a
Multiply both sides of the equation by 2x+1.
2x^{2}+x=x^{2}-a
Use the distributive property to multiply x by 2x+1.
x^{2}-a=2x^{2}+x
Swap sides so that all variable terms are on the left hand side.
-a=2x^{2}+x-x^{2}
Subtract x^{2} from both sides.
-a=x^{2}+x
Combine 2x^{2} and -x^{2} to get x^{2}.
\frac{-a}{-1}=\frac{x\left(x+1\right)}{-1}
Divide both sides by -1.
a=\frac{x\left(x+1\right)}{-1}
Dividing by -1 undoes the multiplication by -1.
a=-x\left(x+1\right)
Divide x\left(1+x\right) by -1.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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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
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