Question

Musa is 47 years old and Dayo is 22 years old. How many years ago was the product of their ages i.e 836 years.​

Answer 1

3 years ago

Explanation:

let m be Musa's age and d be Dayo's age

let x be number of years ago

m = 47

d = 22

(m - x)(d - x) = 836

(47 - x)(22 - x) = 836

1034 - 69x + x² = 836

x² - 69x + 198 = 0

This is in standard from ax² + bx + c = 0

Factor to be (x+q)(x+p)=0

p*q = c = 198

p+q = b = -69

198 = (-3)*(-66)

(-3) + (-66) = -69

Factored form is:

(x - 66)(x - 3) = 0

Set each bracket to 0

x - 66 = 0

x = 66 <= This number is inadmissable because neither Musa nor Dayo reached age 66.

x - 3 = 0

x = 3

The product of their ages was 836 3 years ago.