Solve for x
x=\frac{5\left(y+1\right)}{21}
Solve for y
y=\frac{21x}{5}-1
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y=\frac{20+1}{5}x-1
Multiply 4 and 5 to get 20.
y=\frac{21}{5}x-1
Add 20 and 1 to get 21.
\frac{21}{5}x-1=y
Swap sides so that all variable terms are on the left hand side.
\frac{21}{5}x=y+1
Add 1 to both sides.
\frac{\frac{21}{5}x}{\frac{21}{5}}=\frac{y+1}{\frac{21}{5}}
Divide both sides of the equation by \frac{21}{5}, which is the same as multiplying both sides by the reciprocal of the fraction.
x=\frac{y+1}{\frac{21}{5}}
Dividing by \frac{21}{5} undoes the multiplication by \frac{21}{5}.
x=\frac{5y+5}{21}
Divide y+1 by \frac{21}{5} by multiplying y+1 by the reciprocal of \frac{21}{5}.
y=\frac{20+1}{5}x-1
Multiply 4 and 5 to get 20.
y=\frac{21}{5}x-1
Add 20 and 1 to get 21.
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}