SOLUTION: Kenneth's age is 5 yrs older than Alvin. Find there present ages if the product of Kenneth's age 4 yrs. from now and Alvin's age 5 yrs. ago is 51.
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Question 12980: Kenneth's age is 5 yrs older than Alvin. Find there present ages if the product of Kenneth's age 4 yrs. from now and Alvin's age 5 yrs. ago is 51. Answer by rapaljer(4671) (Show Source):
You can put this solution on YOUR website! Let x = Alvin's age
x+5 = Kenneth's age
x+5 + 4 = x+9 = Kenneth's age 4 yrs from now
x-5 = Alvin's age 5 years ago.
Equation:
Product of (Kenneth 4 years from now)x (Alvin 5 years ago) = 51
(x+9)(x-5) = 51
Guess what! It factors!!
x= -12, x= 8
An age cannot be negative, so
x= 8 Alvin's age
x+5 = 13 Kenneth's age
Check: In 4 years Kenneth will be 17, and 5 years ago, Alvin was 3. The product of 17*3 is 51.
It checks.
