Question

The product of Ramu age 5 year ago with his age 7 year later is 28 Ramu present age is

Answer 1

ANSWER :

Ramu's age = 7 years

EXPLANATION :

Let his age be = ' x '

5 years ago, his age will be = ' x - 5 '

7 years ago, his age will be = ' x + 7 '

Therefore,

( x - 5 )(x + 7 ) = 28

${x}^{2} + 7x - 5x - 35 = 28$

${x}^{2} + 2x - 35 - 28 = 0$

${x}^{2} + 2x - 63 = 0$

${x}^{2} - 7x + 9x - 63 = 0$

$x(x - 7) + 9(x - 7) = 0$

$(x + 9)(x - 7) = 0$

$(x + 9) = 0 \: \: \: or \: \: (x - 7) = 0$

$x = - 9 \: \: or \: x = 7$

(discarding x = -9 since negative)

Therefore Ramu's age is 7 years.

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Verification

= ( 7 - 5 )( 7 + 7)

= 2 × 14

= 28