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?
s = m
(s-18)*4 = m
4s-72 = s
3s = 72
s = 24
they both started with 24
sally sold 18, leaving her with 6. marta then had 4 times that.
24
To solve this problem, let's assign variables to the number of postcards each girl had initially. Let's say Sally had "x" postcards and Marta also had "x" postcards.
According to the given information, after Sally sold 18 postcards, Marta had 4 times as many postcards as Sally. Therefore, Marta had 4 * (x - 18) postcards.
Since both girls initially had the same number of postcards, we can set up an equation:
x = 4 * (x - 18)
Now, let's solve this equation to find the value of x, which represents the initial number of postcards each girl had.
Expanding the equation:
x = 4x - 72
Moving the variables to one side:
x - 4x = -72
-3x = -72
Divide both sides by -3 to isolate x:
x = (-72) / (-3)
x = 24
Therefore, each girl initially had 24 postcards.
a box of chalk and 2 staplers cost ten dollars. three boxes of chalk and two staplers cost eighteen dollars. find the total of one box of chalk and one stappler
18+6=24
24-18=6
6x4=24
They both started off with 24 cards