How many solutions can a nonhomogeneous system of linear (algebraic) equations have? what if the system is homogeneous?

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 ?

He concluded that a heavier object dropped from the same height as a lighter object will land

Find the area of a parallelogram with the given vertices. p(-2, -5), q(9, -5), r(1, 5), s(12, 5)