Answer:
Her test score would be an 85 because 5x3=15 and then you would subtract 15 from 100 which would be 85
equation would be x=100-(5y)
Answer:
$800
Step-by-step explanation:

9514 1404 393
Answer:
no solution
Step-by-step explanation:
The equations describe parallel lines. There are no values of x and y that will satisfy both equations.
In standard form, the two equations are ...
3x +7y = 21
3x +7y = -42 . . . . . with positive leading coefficient
If (x, y) values satisfy the first equation, they cannot satisfy the second equation, and vice versa.
I would say that the last one would be the most accurate.