Answer:
[tex]x=\frac{125}{6},\\y=11[/tex]
Step-by-step explanation:
The angles marked [tex]7x-15[/tex] and [tex]5x-5y[/tex] are co-interior angles. Since all co-interior angles are supplementary (add up to 180 degrees), we have the following equation:
[tex]7x-15+5x-5y=180[/tex]
The two angles marked [tex]4x+4y[/tex] and [tex]2x+y[/tex] are also co-interior angles, thus must also add to 180 degrees.
Therefore, we have the following system of equations:
[tex]\begin{cases}7x-15+5x-5y=180,\\4x+4y+2x+y=180\end{cases}[/tex]
Combine like terms:
[tex]\begin{cases}12x-5y-15=180,\\6x+5y=180\end{cases}[/tex]
Divide the first equation by -2 and add both equations to get rid of [tex]x[/tex]:
[tex]\begin{cases}-6x+2.5y=-97.5,\\6x+5y=180\end{cases},\\-6x+6x+2.5y+5y=82.5,\\7.5=82.5,\\y=\boxed{11}[/tex]
Now substitute [tex]y=11[/tex] into any equation with [tex]x[/tex]:
[tex]6x+5y=180,\\6x+5(11)=180,\\6x+55=180,\\6x=125,\\x=\boxed{\frac{125}{6}}[/tex]
Verify that these two solutions work:
[tex](7(\frac{125}{6})-15)+(5(\frac{125}{6})-5(11))=180\:\checkmark,\\\\(4(\frac{125}{6})+4(11))+(2(\frac{125}{6})+11)=180\:\checkmark[/tex]
