How many multiples of 5 are there between 81 and 358?

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a

You have 12 balloons to blow up for your birthday party. you blow up 1/3, and your friend blows up 5 of them. what fraction of the baloons still need blowing up

Atransformation t : (x, y) (x-5,y +3) the image of a(2,-1) is