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?
4(x-18)=x
4x-72=x
3x=72
x=72/3
x=24
First multiply 18 by 4 it equals 72.
Divide 72 by 3 and you get your answer ( the answer is 24
Ew, that doesn’t make sense why are you dividing by 3???
Thanks!
thanks for helping me :)
To solve this problem, let's break it down step by step.
Let's start by assigning variables to the unknown quantities. Let's denote the initial number of postcards that Sally and Marta had as "S" and "M" respectively.
According to the first sentence, Sally and Marta had the same number of postcards. Therefore, S = M.
After Sally sold 18 of her postcards, we can subtract 18 from S and obtain the new number of postcards she has, which we can call S - 18.
According to the second sentence, Marta had 4 times as many postcards as Sally after she sold 18. Therefore, we have the equation: M = 4 * (S - 18).
Substituting S for M from the first sentence, we get: S = 4 * (S - 18).
Now, let's solve this equation to find the value of S, which represents the original number of postcards Sally had.
Expanding the equation, we get: S = 4S - 72.
Combining like terms, we have: -3S = -72.
Dividing both sides by -3, we get: S = 24.
Therefore, Sally had 24 postcards to begin with.
Since Sally and Marta had the same number of postcards to start with, Marta also had 24 postcards.