х^-8 1 1
11) ------------ = х^-2 = ----- = --------- = 9
х^-4х^-2 х^2 (1/3)^2
4а^2–25 -24,99
13) -------------- = --------- = –1,7
15–6а 14,7
а^2–16а+64 (а–8)^2 а–8
15) ------------------ = ------------ = – ------ =
64–8а -8(а–8) 8
-8,4
= – ------ = 1,05
8
с^2–2с 16–6с с^2–2с 16–6с
17) ----------- – --------- = --------- + ---------
с–4 4–с с–4 с–4
с^2–2с+16–6с с^2–8с+16
= ---------------------- = --------------- =
с–4 с–4
(с–4)^2
= ---------- = с–4 = –3,5–4 = –7,5
с–4