Explain shaggy thinking

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)

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

Angela is buying a dress that is on sale for 20% off. if the original price of the dress is $40.00, how much money is angela saving on the dress? a. $0.80 b. $3.20 c. $32.00 d. $8.00