Answer:
5 years
Explanation:
Let x be the unknown numer of years ago when the product of the man and his child's age was 96.
》 x years ago, the man's age = 37 - x
the child's age = 8 - x
(37 - x)(8 - x) = 96
296 - 37x - 8x + x² = 96
x² - 45x - 296 - 96 = 0
x² - 45x - 200 = 0
x² - 5x - 40x - 200 = 0
x(x - 5) -40(x - 5) = 0
(x - 5)(x - 40) = 0
x = 5 years ago or x = 40 years ago
but x = 40 > son's present age.
Thus, x = 5.
Therefore, 5 years ago the product of the ages of the man and his child was 96.