DESPERATE HELP! solving word problems using the 5 steps for problem solving

Question

Paint express charges $30.00 per gal.of paint plus $1.10 per sq.ft. of wall space. Color creations charges $24.00 per gal. plus $1.20 per sq.ft. of wall space. /robert estimates he will need 4 gals. of paint for the rooms he'd need painted. How much space would make paint express than color creations?

Answer 1

P(s,g)=30g+1.10s is the cost in dollars of Paint Express's charge, where s is the space in square feet, and g is the number of gallons of paint, while:

C(s,g)=24g+1.20s is Color Creations' cost for the same space.

If P>C, when g=4:

120+1.10s>96+1.20s, 24>0.10s, 240>s, so Paint Express would charge more than Color Creations if the space was less than 240 square feet.

When s=240 their charges would be the same: 120+264=96+288=$384.

When s>240 Color Creations would charge more.