Solve for x
x=9
Graph
Share
Copied to clipboard
4\left(x+3\right)=3\left(x+7\right)
Variable x cannot be equal to -7 since division by zero is not defined. Multiply both sides of the equation by 4\left(x+7\right), the least common multiple of x+7,4.
4x+12=3\left(x+7\right)
Use the distributive property to multiply 4 by x+3.
4x+12=3x+21
Use the distributive property to multiply 3 by x+7.
4x+12-3x=21
Subtract 3x from both sides.
x+12=21
Combine 4x and -3x to get x.
x=21-12
Subtract 12 from both sides.
x=9
Subtract 12 from 21 to get 9.
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}