rohan's mother is 26 years older than him. the product of their ages (in years) 3 years from now will be 360. we need to find rohan's present age
Answers
In Present
Let Rohan Age=x years
Then Mother Age=(x+26) years
After 3 years
Rohan Age=(x+3) years
Mother Age=(x+26+3) years
Product=360 years
A/Q
(x+3)(x+26+3)=360
(x+3)(x+29)=360
x²+29x+3x+87=360
x²+32x+87=360
x²+32x+87-360=0
x²+32x-273=0
By Middle Term Spilliting
x²+(39-7)x-273=0
x²+39x-7x-273=0
x(x+39)-7(x+39)=0
=(x-7)(x+39)=0
A/Q
x-7=0
x=0+7
x=7
x+39=0
x=0-39
x=-39
Hence Age Can't be in negative
x=7 years
Rohan Age=x=7 years
Mother Age=x+26=7+26=33 years
Answer :-
Explanation :-
Let, Rohan's present age be x years.
So, according to the question, we can say that her mother's age would be (x + 26) years
After 3 years, Rohan's age = x + 3
Her mother's age would be = x + 26 + 3 = x + 29 years.
Given, their product is 360
→ (x + 3)(x + 29) = 360
→ x² + 29x + 3x + 87 = 360
→ x² + 32x + 87 - 360 = 0
→ x² + 32x - 273 = 0
→ x² + 39x - 7x - 273 = 0
(By splitting the middle terms)
→ x(x + 39) - 7(x + 39) = 0
→ (x - 7)(x + 39) = 0
→ (x - 7) = 0/(x + 39)
→ x - 7 = 0
→ x = 7
Similarly, x = -39
But, age cannot be negative, hence x = 7 years.
So, present age of Rohan is 7 years.