hi,
you must replace x by the number between parenthese.
I show you with the first one and let you do the second one
p(x) = 11x^5 -11x^4 - 5x^2 +15x-8
p(-4) = 11 (-4)^5 - 11 (-4)^4 -5(-4)² +15(-4) -8
p(-4) = 11 ( -1024- 256) - 5*16 -60-8
p(-4) = 11 ( -1280) -80-60-8
p(-4) = - 14080 - 148
p(-4) = - 14 228