2-5 ! explain how you got the answers too! i more want to understand the math than get the answer

Translate this phrase into an algebraic expression. 21 more than twice goran's savings use the variable g to represent goran's savings. need to know fast.

What set does not contain -3 the set of all real numbers the set of all integers the set of all whole numbers the set of all rational numbers

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