Question

a) John is 3 years older than his brother Brian, the product of their ages is 54 i) Express this information in equation form ii) Show this information as a quadratic equation iii) Hence, solve the equation to find their individual ages

Answer 1

Brian is 6 years old, John is 9 years old

Explanation:

i.

J = 3 + B

J x B = 54

ii.

(3 + B) x B = 54

B² + 3B = 54

iii.

(B + 9)(B - 6) = 0

B = -9 or 6 -- -9 is irrational as one cannot be negative years old

Brian = 6 years old; therefore, John = 9 years old