Solve 3x+7=1.

3x+7 = 1. We can describe this equation as a stroy. First x was multiplied by 3 and then 7 was added to it to get 1. Now we need to reverse the story. 
last thing done was +7, so reversing it gives us -7. 
1 -7 = -6 
then it was multiplied by 3, so to reverse it we need to divide by 3. 

-6 /3 = -2 

that means x=-2

we can check the answer by substituting x=-2 to the equation and see if it holds. 

3(-2) + 7 = -6 +7 = 1 

correct!