-9x4(5x6 + 11x5)

Multiply the -9 by the 5 getting -45

So far you have: -45

Multiply the x4 by the x6 by adding 
the exponents and getting x10

Now so far you have -45x10

Multiply the -9 by the +11 getting -99

Now so far you have -45x10 - 99

Multiply the x4 by the x5 by 
adding the exponents and getting x9

Now so far you have -45x10 - 99x9

and that's the final answer.

Edwin