Answer:
Both graphs can be used.
Step-by-step explanation:
because the time and the difficultly of the grade both depend on how long they take. Therefore it would be both graphs can be used.
how?
jkbgf7jhfdt7jceru9onvdtihdr
180 - 152 = 28
2x + 28 = 180
2x = 152
x = 76