Bài 3:
Chiều rộng là:
\(\dfrac{11}{4}-\dfrac{3}{2}=\dfrac{11}{4}-\dfrac{6}{4}=\dfrac{5}{4}\left(m\right)\)
Chu vi là:
\(\left(\dfrac{11}{4}+\dfrac{5}{4}\right)\cdot2=\dfrac{16}{4}\cdot2=4\cdot2=8\left(m\right)\)
Diện tích là:
\(\dfrac{11}{4}\cdot\dfrac{5}{4}=\dfrac{55}{16}\left(m^2\right)\)
bài 1 :
a) \(3\dfrac{4}{5}\)= \(\dfrac{19}{5}\) b) \(4\dfrac{3}{5}\)=\(\dfrac{23}{5}\)
c) \(11\dfrac{12}{13}\)= \(\dfrac{155}{13}\) d) 12 \(\dfrac{11}{13}\)= \(\dfrac{167}{13}\)
bài 1
a)
\(3\dfrac{4}{5}=\dfrac{3x5+4}{5}=\dfrac{19}{5}\)
b)
\(4\dfrac{3}{5}=\dfrac{4x5+3}{5}=\dfrac{23}{5}\)
c)
\(11\dfrac{12}{13}=\dfrac{11x13+12}{13}=\dfrac{155}{13}\)
d)
\(12\dfrac{11}{13}=\dfrac{12x13+11}{13}=\dfrac{167}{13}\)
bài 2
a)\(3\dfrac{3}{4}+1\dfrac{1}{2}=\dfrac{3x4+3}{4}+\dfrac{1x2+1}{2}=\dfrac{15}{4}+\dfrac{3}{2}=\dfrac{21}{4}\)
b)\(3\dfrac{3}{4}-1\dfrac{1}{2}=\dfrac{15}{4}-\dfrac{3}{2}=\dfrac{15}{4}-\dfrac{6}{4}=\dfrac{9}{4}\)
c)\(3\dfrac{3}{4}x1\dfrac{1}{2}=\dfrac{15}{4}x\dfrac{3}{2}=\dfrac{45}{8}\)
d)\(3\dfrac{3}{4}:1\dfrac{1}{2}=\dfrac{15}{4}:\dfrac{3}{2}=\dfrac{15}{4}.\dfrac{2}{3}=\dfrac{5}{2}\)
1.a. \(3\dfrac{4}{5}=3+\dfrac{4}{5}=\dfrac{19}{5}\)
b. \(4\dfrac{3}{5}=4+\dfrac{3}{5}=\dfrac{23}{5}\)
c. \(11\dfrac{12}{13}=11+\dfrac{12}{13}=\dfrac{155}{13}\)
d. \(12\dfrac{11}{13}=12+\dfrac{11}{13}=\dfrac{167}{13}\)
2.
a. \(3\dfrac{3}{4}+1\dfrac{1}{2}=\dfrac{15}{4}+\dfrac{3}{2}=\dfrac{15}{4}+\dfrac{6}{4}=\dfrac{15+6}{4}=\dfrac{21}{4}\)
b. \(3\dfrac{3}{4}-1\dfrac{1}{2}=\dfrac{15}{4}-\dfrac{3}{2}=\dfrac{15}{4}-\dfrac{6}{4}=\dfrac{15-6}{4}=\dfrac{9}{4}\)
c. \(3\dfrac{3}{4}\) x \(1\dfrac{1}{2}=\dfrac{15}{4}\) x \(\dfrac{3}{2}\) = \(\dfrac{45}{8}\)
d. \(3\dfrac{3}{4}:1\dfrac{1}{2}=\dfrac{15}{4}:\dfrac{3}{2}=\dfrac{15}{4}\) x \(\dfrac{2}{3}=\dfrac{5}{2}\)
3.
Đổi \(2\dfrac{3}{4}m=\dfrac{11}{4}m;1\dfrac{1}{2}m=\dfrac{3}{2}m\)
Chiều rộng là:
\(\dfrac{11}{4}-\dfrac{3}{2}=\dfrac{5}{4}\left(m\right)\)
Chu vi nhình chữ nhật là:
\(\left(\dfrac{11}{4}+\dfrac{5}{4}\right)\)x 2 = 8(m)
Diện tích hình chữ nhật là:
\(\dfrac{11}{4}\) x \(\dfrac{5}{4}=\dfrac{55}{16}\left(m^2\right)\)
Đáp số: \(8\left(m\right);\dfrac{55}{16}\left(m^2\right)\)
đổi \(2\dfrac{3}{4}=\dfrac{11}{4}\)
chiều rộng hình chữ nhật là
\(\dfrac{11}{4}-1\dfrac{1}{2}=\dfrac{5}{4}m\)
chu vi HCN là
\(2x\left(\dfrac{11}{4}+\dfrac{5}{4}\right)=8m\)
diện tích HCN là
\(\dfrac{11}{4}x\dfrac{5}{4}=\dfrac{55}{16}m^2\)
bài 2 :
a) \(3\dfrac{3}{4}+1\dfrac{1}{2}=\dfrac{15}{4}+\dfrac{3}{2}=\dfrac{15}{4}+\dfrac{6}{4}=\dfrac{21}{4}\)
b) \(3\dfrac{3}{4}-1\dfrac{1}{2}=\dfrac{15}{4}-\dfrac{3}{2}=\dfrac{15}{4}-\dfrac{6}{4}=\dfrac{9}{4}\)
c) \(3\dfrac{3}{4}x1\dfrac{1}{2}=\dfrac{15}{4}x\dfrac{3}{2}=\dfrac{45}{8}\)
d) \(3\dfrac{3}{4}:1\dfrac{1}{2}=\dfrac{15}{4}:\dfrac{3}{2}=\dfrac{15}{4}x\dfrac{2}{3}=\dfrac{30}{12}\)
dấu \(x\) là dấu nhân nha
