Solve for x x+y=9.0 0.50x+0.20y=3.90

$x + y = 9$ $0.5 x + 0.2 y = 3.9$

The simplified system is the arbitrary solution of the original system of equations.

$y = 9 - x$

$y = 19.5 - 2.5 x$

Simplify the right side.

Reorder $9$ and $- x$ .

$y = - x + 9$

$y = 19.5 - 2.5 x$

$y = - x + 9$

$y = 19.5 - 2.5 x$

Simplify the right side.

Reorder $19.5$ and $- 2.5 x$ .

$y = - 2.5 x + 19.5$

$y = - x + 9$

$y = - 2.5 x + 19.5$

$y = - x + 9$