Solve for x
x=3
Graph
Share
Copied to clipboard
\frac{9}{4}x-\frac{15}{4}=x
Divide each term of 9x-15 by 4 to get \frac{9}{4}x-\frac{15}{4}.
\frac{9}{4}x-\frac{15}{4}-x=0
Subtract x from both sides.
\frac{5}{4}x-\frac{15}{4}=0
Combine \frac{9}{4}x and -x to get \frac{5}{4}x.
\frac{5}{4}x=\frac{15}{4}
Add \frac{15}{4} to both sides. Anything plus zero gives itself.
x=\frac{15}{4}\times \frac{4}{5}
Multiply both sides by \frac{4}{5}, the reciprocal of \frac{5}{4}.
x=\frac{15\times 4}{4\times 5}
Multiply \frac{15}{4} times \frac{4}{5} by multiplying numerator times numerator and denominator times denominator.
x=\frac{15}{5}
Cancel out 4 in both numerator and denominator.
x=3
Divide 15 by 5 to get 3.
Examples
Quadratic equation
{ 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}