3/4 times 4/8 Plz Help You will get 30 points

The value √10 and √15 are plotted on the number line

Ireally need subtract and simplify.(-y^2 – 4y - 8) – (-4y^2 – 6y + 3)show your work, ! i will mark you brainliest but you have to show your work.

Cd is the perpendicular bisector of both xy and st, and cy=20. find xy.