Hello!
Let's remember the property of multiplication of two equal values with0 different exponents:
We'll have to keep the base and add the exponents.
Now, let's try to solve your exercise:
[tex]x^{12}\cdot x^n=x^{12+n}[/tex]What value when added to 12, results in 12?
Just 0, right? Because 12 + 0 = 12
So, let's replace it in the equation:
[tex]\begin{gathered} x^{12}\cdot x^0=x^{12+0} \\ x^{12}_{}\cdot1=x^{12} \end{gathered}[/tex]Also, you must remember that any number when elevated to exponent 0, equals 1, so x^12 * 1 = x^12.
In this exercise, the value of N is 0.