Y=3x y=18 solve for x

Abike shop sells you a bicycle for $63 and a helmet for $21. the total cost is 150% of what the shop spent originally. how much did the shop spend originally? how much profit did the bike shop earn by selling the bicycle and helmet to you ?

How do i do this activity, is appreciated

At $1.32 million, they closed last month percent above what they paid in 2007." how much did they pay in 2007?