Chiều dài hình chữ nhật trồng được là:

5,5:\(\dfrac{1}{4}\)=22(khóm hoa)

Chiều rộng hình chữ nhật trồng được là:

3,75:\(\dfrac{1}{4}\)=15(khóm hoa)

Số khóm hoa trồng được là:

[(22+15).2]-4=70(khóm hoa)

Vậy trồng được 70 khóm hoa.

a) \(\dfrac{1}{5}\)+\(\dfrac{4}{5}\):x=0,75

\(\dfrac{1}{5}\)+\(\dfrac{4}{5}\):x=\(\dfrac{3}{4}\)

\(\dfrac{4}{5}\):x=\(\dfrac{3}{4}\)-\(\dfrac{1}{5}\)

\(\dfrac{4}{5}\):x=\(\dfrac{11}{20}\)

x=\(\dfrac{16}{11}\)

Vậy x=\(\dfrac{16}{11}\)

b)x+\(\dfrac{1}{2}\)=1-x

2x=-\(\dfrac{1}{2}\)

2x=\(\dfrac{1}{2}\)

x=\(\dfrac{1}{4}\)

Vậy x=\(\dfrac{1}{4}\)

a)\(\dfrac{2}{3}\).\(\dfrac{5}{4}\)-\(\dfrac{3}{4}\).\(\dfrac{2}{3}\)=\(\dfrac{2}{3}\).(\(\dfrac{5}{4}\)-\(\dfrac{3}{4}\))=\(\dfrac{2}{3}\).\(\dfrac{1}{2}\)=\(\dfrac{1}{3}\)

b)2.\(\left(\dfrac{-3}{2}\right)^2\)-\(\dfrac{7}{2}\)=2.\(\dfrac{9}{4}\)-\(\dfrac{7}{2}\)=\(\dfrac{9}{2}\)-\(\dfrac{7}{2}\)=1

c) \(\dfrac{-3}{4}\).5\(\dfrac{3}{13}\)-0,75.\(\dfrac{36}{13}\)=\(\dfrac{3}{4}\).5\(\dfrac{3}{13}\)-\(\dfrac{3}{4}\).\(\dfrac{36}{13}\)

=\(\dfrac{-3}{4}\)(5\(\dfrac{3}{13}\)+\(\dfrac{36}{13}\))

=\(\dfrac{-3}{4}\).8

=-6

a)\(\dfrac{2}{3}\).\(\dfrac{5}{4}\)-\(\dfrac{3}{4}\).\(\dfrac{2}{3}\)=\(\dfrac{2}{3}\).(\(\dfrac{5}{4}\)-\(\dfrac{3}{4}\))=\(\dfrac{2}{3}\).\(\dfrac{1}{2}\)=\(\dfrac{1}{3}\)