What are you looking for? The X? Tell us exactly.
Answer:
Step-by-step explanation:
X = number of Yan's marbles. x-3 = number of Geraldo's marbles
annswer: x + (x - 3) = 21
hopes this helps :)
We set up the equation 580/4 = 725/x. Since we know these are proportional, we can cross-multiply and solve to get x = 5.