Карточка 4: 1) 18k/(24k²) =; 2) 14a³b²/(21ab⁴) =; 3) (49−d²)/(7+d) =; 4) (10r−30)/(5r−15) =; 5) (p²+2p)/(p²−4) =; 6) (4u−20)/(u²−5u) =.

1. \(\dfrac{18k}{24k^2}=\dfrac{3}{4k}\).
2. \(\dfrac{14a^3b^2}{21ab^4}=\dfrac{2a^2}{3b^2}\).
3. \(\dfrac{49-d^2}{7+d}=\dfrac{(7-d)(7+d)}{7+d}=7-d\).
4. \(\dfrac{10r-30}{5r-15}=\dfrac{10(r-3)}{5(r-3)}=2\).
5. \(\dfrac{p^2+2p}{p^2-4}=\dfrac{p(p+2)}{(p-2)(p+2)}=\dfrac{p}{p-2}\).
6. \(\dfrac{4u-20}{u^2-5u}=\dfrac{4(u-5)}{u(u-5)}=\dfrac4u\).

Ответ: 1) \(\frac3{4k}\); 2) \(\frac{2a^2}{3b^2}\); 3) \(7-d\); 4) \(2\); 5) \(\frac{p}{p-2}\); 6) \(\frac4u\).