Which expression is equivalent to (10 + 7 r - r 2) + (-6 r 2 - 18 + 5 r )

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Graph the line that represents a proportional relationship between d and t with the property that an increase of 33 units in t corresponds to an increase of 44 units in d. what is the unit rate of change of dd with respect to t? (that is, a change of 11 unit in t will correspond to a change of how many units in d? )

Avery’s piggy bank has 300 nickels, 450 pennies, and 150 dimes. she randomly picks three coins. each time she picks a coin, she makes a note of it and puts it back into the piggy bank before picking the next coin.