SOLUTION: Using only one variable, The sum of Robin and Bruno's age is 45. Seven years ago, Robin was 16 years more than one-half as old as Bruno was then. How old is Bruno?

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Question 1064206: Using only one variable, The sum of Robin and Bruno's age is 45. Seven years ago, Robin was 16 years more than one-half as old as Bruno was then. How old is Bruno?
Found 2 solutions by addingup, MathTherapy:
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
R+B = 45, so R = 45-B
------------------------------
R-7 = 16+1/2(B-7) now substitute for R
(45-B)-7 = 16+1/2B-3.5
45-B = 23+1/2B-3/2
45-B = 19.5+1/2B
25.5 = 1.5B
B = 25.5/1.5 = 17 Bruno is 17
And Robin is 45-17 = 28

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Using only one variable, The sum of Robin and Bruno's age is 45. Seven years ago, Robin was 16 years more than one-half as old as Bruno was then. How old is Bruno?
Let Bruno's age be B
Then Robin's is: 45 - B
Also,
- 2B = B - 7 - 44 ------ Multiplying by LCD, 2
- 2B - B = - 51
- 3B = - 51
B, or Bruno is: highlight_green%28matrix%281%2C4%2C+%28-+51%29%2F%28-+3%29%2C+or%2C+17%2C+years-old%29%29