Solve for a
a=9
Share
Copied to clipboard
\left(a-6\right)\times 3+5=\left(a-7\right)\times 7
Variable a cannot be equal to any of the values 6,7 since division by zero is not defined. Multiply both sides of the equation by \left(a-7\right)\left(a-6\right), the least common multiple of a-7,a^{2}-13a+42,a-6.
3a-18+5=\left(a-7\right)\times 7
Use the distributive property to multiply a-6 by 3.
3a-13=\left(a-7\right)\times 7
Add -18 and 5 to get -13.
3a-13=7a-49
Use the distributive property to multiply a-7 by 7.
3a-13-7a=-49
Subtract 7a from both sides.
-4a-13=-49
Combine 3a and -7a to get -4a.
-4a=-49+13
Add 13 to both sides.
-4a=-36
Add -49 and 13 to get -36.
a=\frac{-36}{-4}
Divide both sides by -4.
a=9
Divide -36 by -4 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}