Name an unknown name.
First of all, let's give this unknown a name, just call it "X"! So the equation becomes 6+x-7=3.
Simplified equation
We just add 7 to both sides of the equation and subtract 6 to get the value of x! The result of this calculation is: x=4.
Solve the problem successfully
According to our method, step by step, we can easily solve this math problem! Son, don't be afraid when you encounter such a problem next time!