Solve {r}{2*(a+b)=72}{4*a=80}

$$\left. \begin{array} { r } { 2 \cdot ( a + b ) = 72 } \\ { 4 \cdot a = 80 } \end{array} \right.$$

Solve for a, b

$$a=20$$

$$b=16$$

Solution Steps

Consider the second equation. Divide both sides by 4.

$$a=\frac{80}{4}$$

Divide 80 by 4 to get 20.

$$a=20$$

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

$$2\left(20+b\right)=72$$

Divide both sides by 2.

$$20+b=\frac{72}{2}$$

Divide 72 by 2 to get 36.

$$20+b=36$$

Subtract 20 from both sides.

$$b=36-20$$

Subtract 20 from 36 to get 16.

$$b=16$$

The system is now solved.

$$a=20 b=16$$