Name: casey

Who is asking: Parent
Level: Secondary

Question:
yeah my son brought home a math worksheet and he was wondering and me too if u could help him and me out . he has problems like this 4n+9=7n+2= ??? and he has to show work so if u could help us out that would be great

Hi Casey
4n + 9 = 7n + 2 =  ??? This is an interesting problem. I would do the original problem in 2 parts.

I would first solve the equation 4n + 9 = 7n + 2. This means that I need to determine the value of "n"" that will make 4n + 9 have the same value as 7n + 2.

4n + 9 = 7n + 2 and so, subtracting 4n from both sides,
4n + 9 - 4n = 7n + 2 - 4n which means
9 = 3n + 2.
Now subtracting 2 from both sides I get
9 - 2 = 3n + 2 - 2, which is
7= 3n and so 7/3 = 3n/3, in other words
7/3 = n.

Now we can do the final part.

When n = 7/3,
4n + 9 = 4(7/3) + 9 = 28/3 + 9 = 28/3 + 27/3 = 55/3.
But n = 7/3 is tha value of n that makes 4n + 9 = 7n + 2, so when n = 7/3, 7n + 2 = 55/3 also.
As a check you can evaluate 7n + 2 when n = 7/3 to ensure that you get 55/3.

Cheers,
Jack