Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Bài giải
\(\frac{2}{3}+\frac{3}{4}+\frac{4}{5}=\frac{40}{60}+\frac{45}{60}+\frac{48}{60}=\frac{133}{60}\)
\(\frac{8}{5}+\frac{7}{6}+\frac{10}{9}+\frac{1}{2}=\frac{144}{90}+\frac{105}{90}+\frac{100}{90}+\frac{45}{90}=\frac{394}{90}\)
\(\frac{15}{17}-\frac{11}{13}+\frac{3}{26}=\frac{390}{442}+\frac{374}{442}+\frac{51}{442}=\frac{815}{442}\)
\(\frac{9}{12}\text{ x }\frac{4}{3}\text{ : }\frac{8}{5}=\frac{9}{12}\text{ x }\frac{4}{3}\text{ x }\frac{5}{8}=\frac{9\text{ x }4\text{ x }5}{12\text{ x }3\text{ x }8}=\frac{5}{8}\)
\(\frac{4}{5}\text{ x }\frac{15}{8}\text{ : }\frac{5}{7}=\frac{4}{5}\text{ x }\frac{15}{8}\text{ x }\frac{7}{5}=\frac{4\text{ x }15\text{ x }7}{5\text{ x }8\text{ x }5}=\frac{21}{10}\)
\(\frac{2}{3}+\frac{3}{4}+\frac{4}{5}=\frac{40}{60}+\frac{45}{60}+\frac{48}{60}=\frac{133}{60}\)
\(\frac{8}{5}+\frac{7}{6}+\frac{10}{9}+\frac{1}{2}=\frac{144}{90}+\frac{105}{90}+\frac{100}{90}+\frac{45}{90}=\frac{197}{45}\)
\(\frac{15}{17}-\frac{11}{13}+\frac{1}{26}=\frac{390}{442}+\frac{374}{442}+\frac{51}{442}=\frac{815}{442}\)
\(\frac{9}{12}\times\frac{4}{3}:\frac{8}{5}=1:\frac{8}{5}=\frac{5}{8}\)
\(\frac{4}{5}\times\frac{15}{8}:\frac{5}{7}=\frac{3}{2}:\frac{5}{7}=\frac{21}{10}\)
a: 5/7+5/4
=20/28+35/28=55/28
b: 3/2-4/6
=9/6-4/6=5/6
c: 5x3/4=15/4
d: 4/6:8=2/3x1/8=2/24=1/12
viết rõ lại cái đề giùm tui tui mới làm được
\(a.32,5-3\cdot0,87=32,5-2,61=29,89\)
\(8,5\cdot\left(1\dfrac{1}{2}+\dfrac{4}{4}\right):5=8,5\cdot\left(\dfrac{3}{2}+\dfrac{4}{4}\right):5\\ =8,5\cdot\left(\dfrac{6}{4}+\dfrac{4}{4}\right):5\\ =8,5\cdot\dfrac{10}{4}:5\\ =\dfrac{85}{4}:5\\ =\dfrac{17}{4}\)
\(b.30,96-6,45+14,4:3=30,96-6,45+4,8\\ =29,31\)
\(\dfrac{2}{5}\cdot\left(\dfrac{4}{5}-\dfrac{1}{2}\right)=\dfrac{2}{5}\cdot\left(\dfrac{8}{10}-\dfrac{5}{10}\right)\\ =\dfrac{2}{5}\cdot\dfrac{3}{10}=\dfrac{3}{25}\)
bài 2
\(a.2,5\cdot12,5\cdot8\cdot0,4=\left(2,5\cdot0,4\right)\left(12,5\cdot8\right)\\ =1\cdot100=100\)
b,\(\dfrac{12}{15}\cdot\dfrac{5}{6}\cdot\dfrac{3}{20}\cdot\dfrac{32}{5}=\dfrac{12\cdot5\cdot3\cdot32}{15\cdot6\cdot20\cdot5}\\ =\dfrac{3\cdot4\cdot5\cdot3\cdot4\cdot8}{3\cdot5\cdot2\cdot3\cdot5\cdot4\cdot5}=\dfrac{16}{25}\)
Bài 1:
a) \(32.5-3\cdot0.87=32.5-2.61=29.89\)
\(8.5\cdot\left(1\dfrac{1}{2}+\dfrac{4}{4}\right):5=8.5\cdot\dfrac{5}{2}:5=\dfrac{17}{2}\cdot\dfrac{5}{2}:5=\dfrac{85}{4}\cdot\dfrac{1}{5}=\dfrac{17}{4}\)
X đầu tiên : 32 phần 32
X thứ hai : 36 phần 120
X thứ ba : 18 phần 21
X - ( 1/4 + 1/8 ) = 5/8
X - 3/8 = 5/8
X = 5/8 + 3/8
X = 1
\(\frac{3}{8}+\frac{9}{5}=\frac{15}{40}+\frac{72}{40}=\frac{87}{40}\)
\(\frac{5}{7}-\frac{4}{9}=\frac{45}{63}-\frac{28}{63}=\frac{17}{63}\)
\(2-\frac{5}{6}=\frac{12}{6}-\frac{5}{6}=\frac{7}{6}\)
\(\frac{7}{8}+\frac{3}{4}=\frac{7}{8}+\frac{6}{8}=\frac{13}{8}\)
\(\dfrac{3}{8}+\dfrac{1}{4}=\dfrac{3}{8}+\dfrac{2}{8}=\dfrac{5}{8}\)
=> Chọn A
\(\frac{33}{5}\times\frac{3}{8}-\frac{3}{8}:\frac{5}{3}-\frac{5}{4}\)
\(=\frac{33}{5}\times\frac{3}{8}-\frac{3}{8}\times\frac{3}{5}-\frac{5}{4}\)
\(=\frac{3}{8}\times\left(\frac{33}{5}-\frac{3}{5}\right)-\frac{5}{4}\)
\(=\frac{3}{8}\times2-\frac{5}{4}\)
\(=\frac{3}{4}-\frac{5}{4}\)
\(=-\frac{1}{2}\)
\(\frac{33}{5}\)x\(\frac{3}{8}\)- \(\frac{3}{8}\):\(\frac{5}{3}\)- \(\frac{5}{4}\)= (\(\frac{33}{5}\)x \(\frac{3}{8}\)) - ( \(\frac{3}{8}\): \(\frac{5}{3}\)) - \(\frac{5}{4}\)= \(\frac{99}{40}\)- \(\frac{9}{40}\)- \(\frac{5}{4}\)= \(\frac{90}{40}\)- \(\frac{5}{4}\)= \(\frac{9}{4}\)- \(\frac{5}{4}\)= \(\frac{4}{4}\)= 1