Solve for x
x = \frac{6430}{81} = 79\frac{31}{81} \approx 79.382716049
Graph
Share
Copied to clipboard
\sqrt{81x-30}=80
Swap sides so that all variable terms are on the left hand side.
81x-30=6400
Square both sides of the equation.
81x-30-\left(-30\right)=6400-\left(-30\right)
Add 30 to both sides of the equation.
81x=6400-\left(-30\right)
Subtracting -30 from itself leaves 0.
81x=6430
Subtract -30 from 6400.
\frac{81x}{81}=\frac{6430}{81}
Divide both sides by 81.
x=\frac{6430}{81}
Dividing by 81 undoes the multiplication by 81.
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}