Solve {l}{87-2y=3}{x+y=7}

$$\left\{ \begin{array} { l } { 87 - 2 y = 3 } \\ { x + y = 7 } \end{array} \right.$$

Solve for y, x

$$x=-35$$

$$y=42$$

Solution Steps

Consider the first equation. Subtract 87 from both sides.

$$-2y=3-87$$

Subtract 87 from 3 to get -84.

$$-2y=-84$$

Divide both sides by -2.

$$y=\frac{-84}{-2}$$

Divide -84 by -2 to get 42.

$$y=42$$

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

$$x+42=7$$

Subtract 42 from both sides.

$$x=7-42$$

Subtract 42 from 7 to get -35.

$$x=-35$$

The system is now solved.

$$y=42 x=-35$$