Answer
$(\displaystyle \frac{260}{17},\frac{123}{17})$
Work Step by Step
$\left\{\begin{array}{llll}
4x & -5y & =25 & /\times(-1)\\
0.5x & +1.5y & =18.5 & /\times 8
\end{array}\right.\quad$ (eliminate x)
$\left\{\begin{array}{lll}
-4x & +5y & =-25\\
4x & +12y & =148
\end{array}\right\}+$
$17y=117$
$y=\displaystyle \frac{123}{17}$
Back-substitute:
$4x-5(\displaystyle \frac{123}{17})=25$
$4x=25+\displaystyle \frac{615}{17}$
$4x=\displaystyle \frac{425+615}{17}$
$4x=\displaystyle \frac{1040}{17}$
$x=\displaystyle \frac{260}{17}$
Solution: $(\displaystyle \frac{260}{17},\frac{123}{17})$
