SOLUTION: David is 5 years older than his sister. If the sum of the squares of their ages is 193, find their ages.
Algebra.Com
Question 1091695: David is 5 years older than his sister. If the sum of the squares of their ages is 193, find their ages.
Answer by htmentor(1343) (Show Source): You can put this solution on YOUR website!
Let D = David's age
Then his sister's age will be D-5
The sum of the squares is 193:
D^2 + (D-5)^2 - 193 = 0
2D^2 - 10D - 168 = 0
D^2 - 5D - 84 = 0
This factors as:
(D+7)(D-12) = 0
Take the positive solution, D = 12
So David is 12 and his sister is 7
RELATED QUESTIONS
David is 5 years older than his sister. if the sum of the squares of their age is 193,... (answered by Alan3354)
ahmed is 7 years older than his sister if the sun of their ages is 21 years find their... (answered by stanbon)
manu is 4 years older than his sister anu. if the sum of their ages is 20 years, find... (answered by homeworkhedgehog)
Jason is 6 years older than his sister. Their mother is years older than the sum of their (answered by mxgirl22)
Alyssa is 12 years older than her sister, Bethany. The sum of their ages is 44. Find... (answered by josgarithmetic)
Pam is 3 years older than her sister, Jan. The sum of their ages is 99. Find their... (answered by ikleyn)
Chris is five years older than his sister. The sum of their ages is 39. Find Chris's... (answered by TimothyLamb)
amar is five years older than his sister , the sum of their ages is 39 . find amar age (answered by Alan3354)
robert is 15 years old than his sister helen. the sum of their ages is 63. find their... (answered by Alan3354)