SOLUTION: Joe is 5 years older than Sally. In 15 years Joe will be 3 times as old as Sally is now. How old is Sally now? Hint: Write Joe's age now in terms of Sally's age now. Then write Joe

Question 147898: Joe is 5 years older than Sally. In 15 years Joe will be 3 times as old as Sally is now. How old is Sally now? Hint: Write Joe's age now in terms of Sally's age now. Then write Joe's age in 15 years using the expression you just wrote for Joe's age now. Then using S for Sally's age now, write the equation with only one variable "S" and solve it.
I need help with this :)
Answer by Fombitz(32388) (Show Source): You can put this solution on YOUR website!
Joe's age is J.
Sally's age is S.
Joe is 5 years older than Sally.
1.
In 15 years, Joe will be J+15.
In 15 years Joe will be 3 times as old as Sally is now.
2.
Substitute J from eq. 1 into eq. 2 to get an equation in S only,
2.

From eq. 1,
1.

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