If 3n+m=14 and n+m=1, find the value of n-m.

Hey there! :D

We can subtract the two equations.

3n+m=14
n+m=1

3n-n=2n

m-m=0

14-1= 13

We are left with:

2n=13

Divide both sides by 2.

n=6.5

Plug that in to find m.

n+m=1

6.5+m=1

Subtract both sides by 6.5.

m=-5.5

Now, put the values for m and n into the last equation for the value.

n-m

6.5-(-5.5)

Two negatives make a positive.

6.5+5.5= 12

The value is 12.

I hope this helps!
~kaikers