Answer:
12 cm
Step-by-step explanation:
So the Pythagorean Theorem states 
If we know what c and a are, we can solve for b by doing

or



The answer for the first one is (3,2) because both lines pass through this point. :)
Y = -2.5x + 45
That's your equation. Your y-intercept would be 45 because that's what she started with. It would be a negative slope as well.