SOLUTION: 21 = 3 a+2 a-1

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Question 214005: 21 = 3
a+2 a-1
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
If you meant:
21/(a+2)=3/(a-1)
Then:
21(a-1)=3(a+2)
21a-21=3a+6
21a-3a=6+21
18a=27
a=27/18
a=3/2 ans.
Proof:
21/(3/2+2)=3/(3/2-1)
21/(7/2)=3/(1/2)
21*2/7=3*2/1
42/7=6
6=6