weight problem: how much does each ball weigh?

[Guest]

Together, a baseball and a football weigh 1.25 pounds, the baseball and a soccer ball weigh 1.35 pounds, and the football and the soccer ball weigh 1.9 pounds. How much does each of the balls weigh?

 

[stapel]

Hint: How much would two baseballs, a football, and a soccer ball weigh? So how much would just the two baseballs weigh?

Eliz.
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Edit: Ne'mind: Answer posted below.

 

[Mrspi]

Together, a baseball and a football weigh 1.25 pounds, the baseball and a soccer ball weigh 1.35 pounds, and the football and the soccer ball weigh 1.9 pounds. How much does each of the balls weigh?

I guess I would approach the problem this way:

let b = weight of one baseball
let f = weight of one football
let s = weight of one soccer ball

Then, from the statements in the problem, we have this:
b + f = 1.25
b + s = 1.35
f + s = 1.9

You can solve the first equation for f:
b + f = 1.25
f = 1.25 - b

You can solve the second equation for s:
b + s = 1.35
s = 1.35 - b

Now, substitute the expressions you have for f and s into the third equation:
f + s = 1.9
(1.25 - b) + (1.35 - b) = 1.9

Can you finish it now?

 

[soroban]

Hello, c4duffy!

Together, a baseball and a football weigh 1.25 pounds,
the baseball and a soccer ball weigh 1.35 pounds,
and the football and the soccer ball weigh 1.9 pounds.
How much does each of the balls weigh?

We have: $\displaystyle \,\begin{array}{ccc}B\,+\,F\;\;\;\;=\;1.25 \\ B\,\;\;\;+\,S\;=\;1.35 \\ \;\;\;F\,+\,S\;=\;1.90\end{array}$


Solve the system of equations:

$\displaystyle \;\;\;B\,=\,0.35,\;F\,=\,0.90,\;S\,=\,1.00$