№2
4x²-1 3x² 4x²-1-3x² x²-1 (x-1)(x+1) x-1 1/3 - 1
-------- - -------- = ------------- = -------- = -------------- = ------ => --------- =
(x+1)² (x+1)² (x+1)² (x+1)² (x+1)(x+1) x+1 1/3 + 1
2 4 2 3 1
- --- : --- = - --- * --- = - --
3 3 3 4 2
№3
a) 4p-q p-5q 5q(5p-q)+4p(p-5q) 25pq-5q²+4p²-20pq
-------- + -------- = ------------------------- = -------------------------- =
12p²q 15pq² 60p²q² 60p²q²
4p²+5pq-5q²
----------------
60p²q²
б) x³ (x+1)(x²-x+1)-x³ x³-x²+x+x²-x+1-x³ 1
x²-x+1 - ----- = --------------------- = ------------------------ = -----
x+1 x+1 x+1 x+1
в) m-3n m+3n (m-n)(m-3n)-(m+n)(m+3n)
----------- - ----------- = ---------------------------------- =
8n(m+n) 8n(m-n) 8n(m-n)(m+n)
m²-3mn-mn+3n²-(m²+3mn+mn+3n²) m²-4mn+3n²-m²-4mn-3n²
------------------------------------------------ = ---------------------------------- =
8n(m-n)(m+n) 8n(m-n)(m+n)
8mn m
- ------------------- = - ---------------
8n(m-n)(m+n) (m-n)(m+n)
г) 3c+7 c-7 7(3c+7)+c(c-7) 21c+49+c²-7c c²+14c+49
--------- + --------- = -------------------- = ------------------- = -------------- =
c(c+7) 7(c+7) 7c(c+7) 7c(c+7) 7c(c+7)
(c+7)² c+7
-------- = ------
c(c+7) c