I need help please 1) George left a 19% tip on a $90 dinner bill. How much was the tip?

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

Tim's phone service charges $23.06 plus an additional $0.22 for each text message sent per month. if tim's phone bill was $28.56, which equation could be used to find how many text messages, x, tim sent last month?

The length of a rectangle plus its width is 25 cm. the area is 156 square cm. what are the length and width of the rectangle? separate the answers with a comma.