(3а²+а-2) / (4-9а²) = (3а²+3а-2а-2) / ((2)²-(3а)²)) = ((3а(а+1)-2(а+1)) / ((2-3а)(2+3а)) = ((3а-2)(а+1)) / (-(3а-2)(2+3а)) =
- ((а+1) / (2+3а)
(3а²+а-2) / (4-9а²) = (3а²+3а-2а-2) / ((2)²-(3а)²)) = ((3а(а+1)-2(а+1)) / ((2-3а)(2+3а)) = ((3а-2)(а+1)) / (-(3а-2)(2+3а)) =
- ((а+1) / (2+3а)