For this case we have a system of two equations with two unknowns:
[tex]y = 9x\\y = 2x + 63[/tex]
Matching we have:
[tex]9x = 2x + 63[/tex]
subtracting 2x on both sides of the equation:
[tex]9x-2x = 2x-2x + 63\\7x = 63[/tex]
Dividing between 7 on both sides of the equation:
[tex]\frac {7x} {7} = \frac {63} {7}\\x = 9[/tex]
We find the value of y:
[tex]y = 9 (9)\\y = 81[/tex]
ANswer:
[tex]x = 9\\y = 81[/tex]
