SOLUTION: Let the operation § be defined for all positive integers a and b by the equation a § b = a + ab For what value of b does

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Question 117750: Let the operation § be defined for all positive integers a and b by the equation
a § b = a + ab
For what value of b does 5 § b = 15?

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Simply use the definition: Since 5 § b = 15, this means 5+5b=15 (just plug in a=5 into a+%2B+ab). Now let's solve for b:




5%2B5b=15 Start with the given equation



5b=15-5Subtract 5 from both sides


5b=10 Combine like terms on the right side


b=%2810%29%2F%285%29 Divide both sides by 5 to isolate b



b=2 Divide

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Answer:
So our answer is b=2

So when b=2, 5 § b = 15 is true