Answer:
-4d
Step-by-step explanation:
L.c.m=15
15×2/5(d-10)-2/3×15(d+6)
3×2(d-10)-2×5(d+6)
6(d-10)-10(d+6)
6d-60-10d-60
6d-10d-60-60
-4d-0
-4d
P(t)=500(1+4t/(50+t^2 ))
P'(t) = 500 [(50+t^2).4 - 4t.2t]/(50+t^2)^2
by the quotient rule
500 (-4t^2 + 200)/(t^2 + 50)^2
Hence
P'(2) = 500 . (-16 + 200)/54^2 ~= 31.6