Answer:
I think the answer is

Step-by-step explanation:
Reason :

Therefore

2x - 3y = 7 and -3x + y = 7..multiply Equation 2 by THREE and add to Equation 1
-9x + 3y = 21...........................watch the y's disappear
-7x........ = 28
x = -4
substitute -4 instead of x in either of the ORIGINAL equations
2x - 3y = 7
2(-4) - 3y = 7
-8 -3y = 7..........add 8 to both sides
-3y = 15
y = -5
im not sure
They are already rounded but 20% and 30% should be correct.
Answer:
Step-by-step explanation:
74*5 = 370
370 - 65 - 70 -70 -80 = 85
So. you need to get 85 on your fifth test.