What would the answer to this math problem?

27.4-3.2×2

Tickets to a science exposition cost $5.75 each for studentd and $7.00 for adults.how many students and adults went if the ticket charge was $42.75

As a self-employed seamstress, you know that it takes 7 yards of material to make 3 jackets. you bought 15 yards of material to make 7 jackets. did you buy enough material? if not, how much were you over or under?

Find the slope and y-intercept of each line y=4x+1