(1) 12ab43a2b=4b3a\dfrac{12ab^4}{3a^2b} = \dfrac{4b^3}{a}3a2b12ab4=a4b3 (2) 12x418xy2=2x33y2\dfrac{12x^4}{18xy^2} = \dfrac{2x^3}{3y^2}18xy212x4=3y22x3 (3) 2xy−3x5xy=2y−35y\dfrac{2xy-3x}{5xy} = \dfrac{2y-3}{5y}5xy2xy−3x=5y2y−3 (4) 3u−2v9u2−4v2=3u−2v(3u−2v)(3u+2v)=13u+2v\dfrac{3u-2v}{9u^2-4v^2} = \dfrac{3u-2v}{(3u-2v)(3u+2v)} = \dfrac{1}{3u+2v}9u2−4v23u−2v=(3u−2v)(3u+2v)3u−2v=3u+2v1 (5) t2+2t−15t2−6t+9=(t+5)(t−3)(t−3)2=t+5t−3\dfrac{t^2+2t-15}{t^2-6t+9} = \dfrac{(t+5)(t-3)}{(t-3)^2} = \dfrac{t+5}{t-3}t2−6t+9t2+2t−15=(t−3)2(t+5)(t−3)=t−3t+5