Today Jane is 3 years old and Kenny is 7 years old
Their situation after 7 years:
The first term is for Jane and the second term is for Kenny.
Therefore when you solve the above written equation, you will get Jane is 3 years old (x=3). Kenny is 7 years old (right now).
3 years later (starting now)
Jane will be 6 and Kenny will be 10 years old. The equation for this situation is:
Solution to a
We are not asked to find the value of
Solution to b
General case for n years:
It is given that the combined age after 7 years is 24.
Jane's age today
So we need to determine
Subtract 18 from both sides (get rid of it from the left)
Divide both sides by 2
Only need the formula !!!!
Let the combined age at initial condition be
Let the combined age at the time interval
So the combined age at year 3 will be
Just added the
After 3 years