You begin with $25 in savings and $50 in checking, each week you deposit $5 into savings and $10 into checking. after how many weeks is the amount in checking twice the amount in savings?

You buy a veido game for $60 and the sales tax is 8% what is the total cost for the game including the sales tax

Let x have probability generating function gx (s) and let un generating function u(s) of the sequence uo, u1, satisfies p(x > n). show that the (1- s)u(s) = 1 - gx(s), whenever the series defining these generating functions converge.

How do you figure out which order to do two step equations in? like which thing do you subtract/add/multiply/divide first? i understand that you do the opposite of whatever's shown on the opposite side, but when?