when x equals -1 you substitute -1 for x in the equation which would look like 5-3(-1) which you would then multiply -3 by -1 and get 3 which 5+3 would equal 8 so f(-1) equals 8
When x equals 3 you substitute 3 for x in the equation which would look like 5-3(3) which you would then multiply -3 by 3 which would give you 5-9 which equals -4 so f(3) equals -4
3/4 x 4/1 = 12/4 simplified to make the denominato to be a 1 so you divide both the numerator, which is 12, and the denominator, which is 4, by 4 so you end up with 3/1 which is 3 cups.
