Solve for y in the first equation:
y=1.25-x (subsitution)

Apply subsitution in the third equation:
z+1.25-x=1.9
z-x=0.65 (set 1)
add set 1 to second equation:

z-x=0.65
x+z=1.35
--------
2z=2

z=1

1-x=0.65
x=0.35

y=1.25-0.35
y=0.9

Hence, a baseball weights 0.35 pounds, a football weights 0.9 pounds and a soccer ball weights 1 pound.
Paul.
Answer by wuwei96815(245)   (Show Source): You can put this solution on YOUR website!
Let x=weight of baseball
Then 1.25-x=weight of football
Then 1.35-x=weight of soccer ball
Then 1.9=(1.25-x) + (1.35-x)

1.9 = 1.25 -x + 1.35 -x
1.9 = 2.60 -2x
1.9-2.6 = -2x
-0.7 = -2x
-0.7/-2 = x
0.35 = x (weight of baseball)

1.25 -x = 0.9 (weight of football)
1.35 -x = 1.0 (weight of soccer ball)

This problem was a little wordy, but I think that we solved it?