Let
x -----> the number of minutes He practices the guitar
y ----> the number of minutes he practices the piano
we know that
x+y=150 ------> equation A
x=y+80 -----> equation B
solve the system of equations
substitute equation B in equation A
(y+80)+y=150
solve for y
combine like terms
2y+80=150
2y=150-80
2y=70
y=35 minutes
Find the value of x
x=y+80
x=35+80
x=115 minutes
therefore
Part B: How much time does Max spend practicing the piano every day? -----> 35 minutes
Part C: Is it possible for Max to have spent 125 minutes practicing the guitar if he practices for a total of exactly 150 minutes and practices the guitar for 80 minutes longer than he practices the piano?
Is not possible, because the number of minutes He practices the guitar is 115 minutes