Sally and Marta had the same number of postcards. After Sally sold 18 of her postcards, Marta had 4 times as many postcards as Sally.
How many postcards did each girl have to begin with?

the equation x - 18 = 4(x - 18)

Step-by-step explanation:

x - 18 = 4x - 72

x - 4x = - 72 + 18

- 3x = - 54

x = 54/3

x = 18

Sally had 36 postcards to begin with (18 + 18)

martha had 0 postcards to begin with

i feel like i did something wrong someone double check this but i think this is the answer.

my answer is$ 12

step-by-step explanation:

because 15 -2=12

a. she will receive a refund of $278.

step-by-step explanation: