I need help with this question!

Evaluate the expression for the given value of the variable 7a - 4a for a =8

Find the slope and the y-intercept if there's one and the equation of the line given these two points( 3, 2) and( 3, -4)

Abakery recorded the number of muffins and bagels it sold for a seven day period. for the data presented, what does the value of 51 summarize? a) mean of bagels b) mean of muffins c) range of bagels d) range of muffins sample # 1 2 3 4 5 6 7 muffins 61 20 32 58 62 61 56 bagels 34 45 43 42 46 72 75