X-3y=15 and y=-3+4 find out the answer if it’s parallel, perpendicular or niether

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 ?

(60 points) explain this in detail

Determine domain and range, largest open interval, and intervals which function is continuous.