aig math
posted by May on .
When 306 stamps were shared among Pat, Kyle, and Ryan, Pat got twice as many stamps as what Kyle and Ryan got together. If Kyle got 18 stamps more than Ryan, how many stamps did Ryan get? Don't forget to show your work.

Pat= x , Kyle= y, Ryan= z
x+y+z= 306
2x= y+z
z+18=y
So from here, you just plug the equations into each other...
2x= y+z
so, 2x= (z+18)+z
so, 2x= 2z+18
so, x= (2z+18) /2
Then you plug this in to the equation: x+y+z= 306
So... (2z+18) /2 + (z+18) + z = 306
Then, 4z+38 = 612
4z = 576
z or Ryan= 144 stamps