Question

The product of Ramu's age before 5 years and his age after 9 years is 15. Find his age.

Answer 1

His age 9 years ago = ( x + 9 ) years. The product of these ages is 15. Hence, Ramu's present age is 6 years.

Answer 2

$\large{\textsf{\red{SOLUTION}}}$

✨ Let the age of Ramu be x .

→ Five years ago , his age = x - 5

→ Nine years ago , his age = x + 9

ATQ ,

(x - 5)(x + 9) = 15

$\sf {x}^{2} + 9x - 5x -45 = 15$

$\sf {x}^{2} +4x - 60= 0$

$\sf {x}^{2} + (10-6)x - 60= 0$

$\sf {x}^{2} +10x - 6x - 60= 0$

$\sf x(x+10) - 6(x+10) = 0$

$\sf x-6=0 \:\:\:\:or\:\:\:\: x+10=0$

$\sf x= 6\:\:\:\:or\:\:\:\: x = -10$

Since x cannot be negative

So , Present age of Ramu is 6 years .

$\rule{200}2$