9514 1404 393
Answer:
8 inches, 13 inches, 19 inches
Explanation:
Let's identify the side lengths (shortest to longest) as a, b, c. Then we have ...
a + b + c = 40 . . . . . . perimeter
2c -a = 30
2a +2b +c = 61
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Subtracting the third equation from twice the first gives ...
2(a +b +c) -(2a +2b +c) = 2(40) -(61)
c = 19 . . . . . simplify
Using this in the second equation, we have ...
2(19) -a = 30
38 -30 = a = 8 . . . . add a-30
Then the first equation reveals b:
8 + b + 19 = 40
b = 40 -27 = 13
The side lengths are 8 in, 13 in, and 19 in.