Answer:
C, D are true
Explanation:
Dina's costs:
Dina paid according to the equation c = 50 + 35m.
When shew joined, the number of the month was 0.
Using 0 for m, we get
c = 50 + 35 * 0
c = 50 + 0
c = 50
Dina paid $50 to join. The since m, the number of months, is being multiplied by 35, she pays $35 per month.
Dina: $50 to join + $35 per month.
Judy's costs:
Judy paid $80 for month 0. That means she paid $80 to join.
In month 1, she had paid a total of $105. Subtract the amount paid at joining, $105 - $80 = $25, and you see that Judy paid $25 per month.
Judy: $80 to join + $25 per month
Now we look at the statements.
A Dina paid a higher amount to join the health club. False. Dina paid $50 which is less than the $80 that Judy paid.
B Judy pays more per month to be a member. False. Judy pays $25 per month which is less than the $35 per month that Dina pays.
C After 1 month, Judy has paid more than Dina. After 1 month, Judy paid $105. After 1 month, Dina paid c = 50 + 35m = 50 + 35 * 1 = 50 + 35 = 85. True. After 1 month, Judy paid $105, which is more than the $85 Dina paid for 1 month.
D After 4 months, Dina has paid more than Judy.
After 4 months, Dina paid c = 50 + 35m = 50 + 35 * 4 = 50 + 140 = 190. After 4 months, Judy paid $25 more than she paid after 3 months. $155 + $25 = $180. After 4 months, Dina paid $190 which is more than the $180 Judy paid. True.