Question

HELP PLEASE! I PUT AN IMAGE BELOW! PLEASE HELP!

Answer 1

`\begin{array}{lcccl} &\stackrel{lbs}{Qty}&\stackrel{\$}{price}&\stackrel{total}{value}\\ \cline{2-4}&\\ \textit{1st candy}&x&0.9&0.9x\\ \textit{2nd candy}&y&0.4&0.4y\\ \cline{1-4} mix&50&0.85&42.5 \end{array}\qquad \qquad \begin{cases} x+y=50\\\\ 0.9x+0.4y=42.5 \end{cases} \\\\[-0.35em] ~\dotfill`
`\stackrel{\textit{using the 1st equation}}{x+y=50\implies y=50-x}\qquad \qquad \stackrel{\textit{substituting on the 2nd equation}}{0.9x~~ + ~~0.4(50-x)~~ = ~~42.5} \\\\\\ 0.9x+20-0.4x=42.5\implies 0.5x+20=42.5\implies 0.5x=22.5 \\\\\\ x=\cfrac{22.5}{0.5}\implies \boxed{x=45}\qquad \qquad \qquad \boxed{\stackrel{50~~ - ~~45}{y=5}}`