How would i solve 5+x=15

5+x=15
You would solve it by first charging the 5 to a -5.
5 —> -5
With that -5 you subtract it from 15.
15-5 = 10
Once you subtract, you should get 10 and then you divide both sides with x. (When a x is by itself it is 1x)
1x/1 = 10/1
Then you should get 10.
X=10

4+2=-2. 1+2=3. y=-2/3x+b. 2=4/3+b. 2/3=b. the answer is y= -2/3x+2/3