Solve for a
a=\frac{3\left(b+7\right)}{4}
Solve for b
b=\frac{4a}{3}-7
Share
Copied to clipboard
4a=21+3b
Add 3b to both sides.
4a=3b+21
The equation is in standard form.
\frac{4a}{4}=\frac{3b+21}{4}
Divide both sides by 4.
a=\frac{3b+21}{4}
Dividing by 4 undoes the multiplication by 4.
-3b=21-4a
Subtract 4a from both sides.
\frac{-3b}{-3}=\frac{21-4a}{-3}
Divide both sides by -3.
b=\frac{21-4a}{-3}
Dividing by -3 undoes the multiplication by -3.
b=\frac{4a}{3}-7
Divide 21-4a by -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}