Question

25. Solve the following system by elimination.6x+ 6 = 3y-15y = -33r - 42A (6,4)B. (-4, -6C. (5, 4)D. (-4, 6)

Answer 1

`\begin{gathered} \text{solve by elimination:} \\ 6x+6=3y \\ -15y=-33x-42 \\ we\text{ can rewrite these equations as} \\ 6x+6=3y \\ -33x-42=-15y \\ to\text{ solve for elimination method, we can multiply by 5 the first equation. We have} \\ 30x+30=15y \\ -33x-42=-15y \\ by\text{ adding those equations one has:} \\ -3x-12=0 \\ -3x=12 \\ x=(12)/(-3) \\ x=-4 \\ \text{now we can substitute x=-4 in the first equation:} \end{gathered}`
`\begin{gathered} 6(-4)+6=3y \\ -24+6=3y \\ 3y=-18 \\ \\ y=(-18)/(3) \\ y=-6 \end{gathered}`
`\text{hence the solution is x=-4 and y=-6}`