SOLUTION: 1. The sum of the ages of two friends is 60. if three times the age of one friend is 9 less than four times the age of the other, how old is each?
2. Rolly is twice as old as hi
Algebra.Com
Question 147760: 1. The sum of the ages of two friends is 60. if three times the age of one friend is 9 less than four times the age of the other, how old is each?
2. Rolly is twice as old as his brother, Darwin. In five years, Darwin will be the same age as his brother ten years ago. What are their present ages?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
1. The sum of the ages of two friends is 60.
x + y = 60
y = (60-x)
;
three times the age of one friend is 9 less than four times the age of the other,
3x = 4y - 9
:
how old is each?
:
Substitute (60-x) for y in the above equation:
3x = 4(60-x) - 9
3x = 240 - 4x - 9
:
3x + 4x = 240 - 9
:
7x = 231
x =
x = 33 yrs old
then
60 - 33 = 27 yrs old
;
:
Check solution in the statement:
three times the age of one friend is 9 less than four times the age of the other,
3(33) = 4(27) - 9
99 = 108 - 9
:
:
2. Rolly is twice as old as his brother, Darwin.
r = 2d
:
In five years, Darwin will be the same age as his brother ten years ago.
d + 5 = r - 10
d = r - 10 - 5
d = r - 15
:
What are their present ages?
:
Substitute 2d for r in the above equation
d = 2d - 15
d - 2d = -15
-d = -15
d = 15 yrs is Darwin's present age
then
2(15) = 30 yrs is Roll's present age
:
Check solution in statement:
In five years, Darwin will be the same age as his brother ten years ago.
15 + 5 = 30 - 10
RELATED QUESTIONS
The sum of the ages of two friends is 60. If three times the age of one friend is 9 less... (answered by mananth)
the sum of the ages of a married couple is 60. if three times the age of the husband is... (answered by solver91311)
a fathers age is three more than four times the age of his son. if the product of their... (answered by harrysgirl143)
the age of two friends are consecutive whole numbers, if the sum of their ages is 25 what (answered by Theo)
The sum of Nora's age and her grandmother's age is 71. Four times Nora's age is 6 less... (answered by checkley75)
The sum of Nora's age and her grandmother's age is 71. Four times Nora's age is 6 less... (answered by eperette)
Three times the age of Felicia is four more than the age of Asare . In three years,the... (answered by richwmiller)
Jack is two years older than three times Nick's age. The sum of their ages 98.
(answered by josgarithmetic,Alan3354)
the age of noelle's dad is six less than three times noelle’s age. the sum of their ages... (answered by josgarithmetic,ikleyn)