IDNStudy.com, ang perpektong platform para sa mabilis at eksaktong mga sagot. Alamin ang mga maaasahang sagot sa iyong mga tanong mula sa aming malawak na kaalaman sa mga eksperto.

The sum of the ages of a mother and daughter is 39. The mother is 3 years younger than the square of the daughter's age. How old is the mother and daughter?

Sagot :

Answer:

The mother is 33 years old, while the daughter is aged 6.

Step-by-step explanation:

  • Interpret the given values into mathematical equations. Let x be the mother's age, and let y be the daughter's age.

"The sum of the ages of a mother and daughter is 39." [Equation 1]
[tex]x+y=39[/tex]

"The mother is 3 years younger than the square of the daughter's age." [Equation 2]
[tex]x=y^2-3[/tex]

  • Since there is an initial value for x, substitute it to equation 1.

[tex]x+y=39\\(y^2-3)+y=39\\y^2+y-3=39\\y^2+y-42=0\\(y+7)(y-6)=0\\\\y=-7 ; y=6[/tex]

  • There is no negative age, hence the daughter's age is 6.
  • To find the mother's age, substitute the daughter's age to any of the two equations.

Via Equation 1:
[tex]x+y=39\\x+6=39\\x=33[/tex]

Via Equation 2:

[tex]x=y^2-3\\x=(6)^2-3\\x=36-3\\x=33[/tex]

  • The mother's age is 33. You may try substituting the values of x and y to Equations 1 & 2 to verify if the solutions of the equations are correct.