The age of a mother is 4 years less than the square of the age of the daughter. Four years later, their ages would be in the ratio of 18: 5. Find the present age of the daughter.
Answers
The age of a mother is 4 years less than the square of the age of the daughter. Four years later, their ages would be in the ratio of 18: 5. Find the present age of the daughter.
let the age of daughter be x
A.T.Q. :-
y = x² - 4
4 Years later :-
age of mother = ( x² - 4 ) + 4 = x²
age of daughter = x + 4
by cross multiplication:-
5x² = 18(x+4)
5x² = 18x + 72
=> 5x² - 18x - 72 = 0
factorizing the equation:-
5x² - 30x + 12x - 72
5x ( x - 6 ) + 12 ( x - 6 )
(x-6) (5x+12)
x-6 = 0
x = 6
hence, the age of daughter is 6 years !
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let the age of daughter be x
A.T.Q. :-
y = x² - 4
4 Years later :-
age of mother = ( x² - 4 ) + 4 = x²
age of daughter = x + 4
\frac{ {x}^{2} }{x + 4} = \frac{18}{5}x+4x2=518
by cross multiplication:-
5x² = 18(x+4)
5x² = 18x + 72
=> 5x² - 18x - 72 = 0
factorizing the equation:-
5x² - 30x + 12x - 72
5x ( x - 6 ) + 12 ( x - 6 )
(x-6) (5x+12)
x-6 = 0
x = 6
hence, the age of daughter is 6 years !