Answer:
y=80, x=140
Step-by-step explanation:
When you solve with subsitution, you first need to subsititute x=-2y+300
This then becomes: 3y=800-4t(-2y+300)
For x=-2y+300
Isolate y for 3y=800-4(-2y+300):
y=80
For x=-2y+300, subsitute y=80
x=-2*80+300= 140
So x=140
