Hello there!
To solve this system using substitution, notice that you already have one variable, x, solved for:
x=5-3y
Now, plug 5-3y in place of x in the other equation, -6x+5y=16:
-6(5-3y)+5y=16
Now simplify:
-6(5-3y)+5y=16
-30+18y+5y=16
-30+23y=16
23y=46
y=2
Now that you have y=2, plug this value in place of y into any of the two equations to solve for x:
x=5-3(2)
x=4-6
x=-1
Therefore, your final answers are that x=-1 and y=2 or (-1,2)