Solve {l}{a=1+2}{b=5+x}{a+b=13}

$$\left. \begin{array} { l } { a = 1 + 2 } \\ { b = 5 + x } \\ { a + b = 13 } \end{array} \right.$$

Solve for a, b, x

$$x=5$$

$$a=3$$

$$b=10$$

Solution Steps

Consider the first equation. Add 1 and 2 to get 3.

$$a=3$$

Consider the third equation. Insert the known values of variables into the equation.

$$3+b=13$$

Subtract 3 from both sides.

$$b=13-3$$

Subtract 3 from 13 to get 10.

$$b=10$$

Consider the second equation. Insert the known values of variables into the equation.

$$10=5+x$$

Swap sides so that all variable terms are on the left hand side.

$$5+x=10$$

Subtract 5 from both sides.

$$x=10-5$$

Subtract 5 from 10 to get 5.

$$x=5$$

The system is now solved.

$$a=3 b=10 x=5$$