Question

Please help, I need to know how to do this in equation form not by graph

Answer 1

`\begin{gathered} \text{ If`

We must solve this sistem of equations, if we multiply the first equation by 3, we get

`\begin{gathered} 6x+18y=216 \\ 6x+12y=156 \end{gathered}`

Now, we will do the first equation minus the second (side by side), so we have

`\begin{gathered} (6x+18y)-(6x+12y)=216-156 \\ 18y-12y=60 \\ 6y=60 \\ y=(60)/(10)=6 \end{gathered}`

Replacing y =6 in the first equation we have

`\begin{gathered} 2x+6(6)=72 \\ 2x+36=72 \\ 2x=72-36 \\ 2x=36 \\ x=(36)/(2) \\ x=18 \end{gathered}`

Thus each ft^2 of grass costs $18, and eachshrub costs $6.