Me with problems 25,26,27,28& 29

Which of the following is true for the relation f(x)=2x^2+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

The multiplicative property of equality states that for real numbers a, b, c, and d, if a = b and c = d, then ac = bd. true false