1.
2 / (х-3)² = 2 / (х-3)(х-3) и (1+х) / (х²-9) = (1+х) / (х-3)(х+3), значит:
2(х+3) / (х-3)²(х+3) и (1+х)(х-3) / (х-3)²(х+3),
2.
13x / (25-x²) = 13х / (5-х)(5+х) и (x-1) / (10+2x) = (х-1) / 2*(5+х), значит:
26х / 2*(25-x²) и (х-1)(5-х) / 2*(25-x²),
3.
(x-3) / (4-x²) и 5x / (x²-4) ⇒ (х-3) / (4-х²) и -5х / (4-х²)