Question 624434
{{{x^(-4) * x^(-7)}}} when multiplying powers of the same base, add exponents
{{{x^(-11)}}}  to change the sign of an exponent, move it 'up or down' and change the sign. Here is the math behind that trick
{{{x^(-11)}}} =
{{{x^(-11) * 1 }}}=
{{{x^(-11) * ((x^11)/(x^11))}}} = 
{{{(X^(-11) * X^11)/ (x^11)}}} =
{{{(x^0 / x^11)}}} x^0 is defined as equating to 1
{{{1/(x^11)}}} which is simply 'moving the negative power from the numerator down to the denominator and changing the sign. The same thing can be done to move a negative exponent in the denominator up to the numerator.

Get it?