What is the ratio of a:b, knowing that (a-b)/(a+b)=3/5
Multiply both sides by 5(a+b); distribute the results on both sides, collect the terms in a and b, then divide through by b.
Or...
Solve the system of equations
a - b = 3 (1)
a + b = 5 (2)
Add (1) and (2) together and you'll get
2a = 8 (3)
Now divide through by 2, then substitute a to the second equation (2), then find the ratio of a : b.
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