Which expression is equivalent to the given expression? (-5y + 21) (y-5)

Really need on these. i have no idea what to do

In the equations, a and b represent the price per night for a room in hotel a and hotel b, respectively, w weeks after september 1 last autumn. what was the price per night in hotel a when it was equal to the price per night in hotel b? a = 240 − 20w b = 320 − 30w

Hello people, i have a math question that i need with, me, i will give the correct one brainiest, and for the other correct people, a and 5 stars.