Solve for k
k=5
Share
Copied to clipboard
k\times 12-40=4k
Variable k cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by k.
k\times 12-40-4k=0
Subtract 4k from both sides.
8k-40=0
Combine k\times 12 and -4k to get 8k.
8k=40
Add 40 to both sides. Anything plus zero gives itself.
k=\frac{40}{8}
Divide both sides by 8.
k=5
Divide 40 by 8 to get 5.
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}