Lowest common multiple of 24 and 30

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.

Barrett is comparing the membership fees for two museums.the art museum charges a one-time fee of $8.25 plus $2.25 per month. the science museum charges a one-time fee of $10.75 plus $3.50 per month. how much does barrett save by joining the art museum instead of the science museum?