Question

the product of ram's age 5 years ago and 7 years hence is 220 find his present age

Answer 1

(x-5)×(x+7)=220
x²+7x-5x-35=220
x²+2x-35=220
x²+7x-5x-35=220
x²+2x=255

Answer 2

Hi !

Ram's present age = x 

Age 5yrs ago = (x - 5) years
Age 7 yrs later = (x+7) years

Given :-

(x - 5) (x + 7)= 220
x² + 7x - 5x - 35 = 220
x² + 2x - 35 - 220
x² + 2x - 255 = 0

Solving by quadratic formula :-

x = -b ± √ b² - 4ac /2a
   = -2 ± √ 2² - 4 × -255 /2
   = -2 ± √ 1024  / 2
   = -2 ± 32/2
   = -2 + 32/2
   = 30/2

present age = 15 yrs