Simple Algebra

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August 16th 2009, 03:19 AM
fvaras89

Simple Algebra

Hello im new to this site.. and was wondering if anyone could help me with this question..

Jennifer is 7 years younger than melisa. In 4 years time Jennifer will be 1 year older than half of Melisas age at that time. How old are Jennifer and Melissa now?

I'd like to see all working out including simultaneous equation.. im very confused.. thank you
August 16th 2009, 03:23 AM
e^(i*pi)

Quote:

Originally Posted by fvaras89

Hello im new to this site.. and was wondering if anyone could help me with this question..

Jennifer is 7 years younger than melisa. In 4 years time Jennifer will be 1 year older than half of Melisas age at that time. How old are Jennifer and Melissa now?

I'd like to see all working out including simultaneous equation.. im very confused.. thank you

Let M be Melissa's age, J be Jennifer's age

At t=0

$J = M - 7$

At t=4

$J+4 +1 = \frac{M+4}{2} \rightarrow J = \frac{M-6}{2}$

You can set these two equations equal and solve for M. From there use the first equation to find J
August 16th 2009, 03:30 AM
fvaras89

i really dont know what to do after, im sorry could u help me out abit more if it doesnt bother u?
August 16th 2009, 03:40 AM
e^(i*pi)

$J = \frac{M-6}{2}$

$J = M - 7$

These two must be equal so we can say that $M-7 = \frac{M-6}{2}$ . Then solve for M

$2M-14 = M-6 \: \rightarrow \: M = 8$

Now M is known use J= M-7 to find J:

$J = 8-7 = 1$