Help with answers please! i have to show work as well

Wrote and expression for the difference of p and 4

Robin spent 25% more time on his research project than he had planned he’s been an extra h ours on the project which of the following expressions could represent the number of hours rob actually spent on the project

X^2/100+y^2/25=1 the y-intercepts are at: a) (-10,0) and (10,0) b) (0,10) and (0,5) c) (0,-5) and (0,5)