Solve for x
x = \frac{18}{5} = 3\frac{3}{5} = 3.6
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15+2x=12x-21
Multiply both sides of the equation by 3.
15+2x-12x=-21
Subtract 12x from both sides.
15-10x=-21
Combine 2x and -12x to get -10x.
-10x=-21-15
Subtract 15 from both sides.
-10x=-36
Subtract 15 from -21 to get -36.
x=\frac{-36}{-10}
Divide both sides by -10.
x=\frac{18}{5}
Reduce the fraction \frac{-36}{-10} to lowest terms by extracting and canceling out -2.
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}