Dylan has a basket of golf balls. He counts 18 white golf balls. The rest of the golf balls are yellow. There are 25 golf balls in the basket. How many golf balls are yellow?

Use the variable b to represent the unknown quantity.

Which equation and solution represents this situation?

18b = 25; b = 7

25b = 18; b = 43

b + 18 = 25; b = 7

b + 25 = 18; b = 43