SOLUTION: Sam is ten less than 3 times as old as Alex. If the difference between their ages is 28, How old is Sam and Alex?

Algebra.Com
Question 1122372: Sam is ten less than 3 times as old as Alex. If the difference between their ages is 28, How old is Sam and Alex?
Answer by Theo(13342)   (Show Source): You can put this solution on YOUR website!
let age of sam be equal to x.
let age of alex be equal to y.

age of sam is 10 less than 3 times the age of alex.

formula for that is x = 3 * y - 10

the difference between their ages is 28.

formula for that is x - y = 28

in this last formula, solve for x to get x = y + 28

in the first formula, replace x with y + 28 to get y + 28 = 3 * y - 10

subtract y from both sides of the equation and add 10 to both sides of the equation to get:

28 + 10 = 3 * y - y

combine like terms to get 38 = 2 * y

solve for y to get y = 38 / 2 = 19

since x = 3 * y - 10, then x must be equal to 47.

you have:

age of sam is 47
age of alex is 19

age of sam is 3 * age of alex minus 10.
that becomes 47 = 3 * 19 - 10 which becomes 47 = 47, confirming this part of the solution is correct.

the difference between their ages is 28.
47 - 19 = 28, confirming this part of the solution is correct.

solution looks good.

sam is 47 and alex is 19.








RELATED QUESTIONS

Mr brown is 3 times as old as Sam. The difference in their ages is 22 how old is... (answered by fractalier,Alan3354)
Sam is twice as old as John was two years ago. If the difference between their ages be 2... (answered by Fombitz)
Joe is twice as old as sam. sam is 3 times as old as paul.The sum of all the ages is 90... (answered by dabanfield)
Sam is twice as old as John was two years ago. If the difference between their ages be 2... (answered by JBarnum)
Alice is twice as old as Judy, who is younger than Alex by 3 years. If the sum of their... (answered by College Student)
George is 2 years older than Sam and Sam is 3 years older than Alex. The total of their... (answered by stanbon,sunny1992)
Five years ago, Sam was seven times as old as his nephew, Bert. Now, Sam is only four... (answered by josgarithmetic,MathTherapy)
George is 2 years older than Sam and Sam is 3 years older than Alex. The total of their... (answered by Fombitz)
John is 4 times as old as Bill, and Bill is 1.5 times as old as Sam. If the sum of their... (answered by ewatrrr)