1/3 + 8/15 : 3/15
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a: =1/8-1/8+2/5=2/5
b: =(-1/15-14/15)+(23/27+31/27)=2-1=1
c: \(=\dfrac{3}{7}\left(\dfrac{22}{21}+\dfrac{5}{21}+\dfrac{15}{21}\right)=\dfrac{3}{7}\cdot2=\dfrac{6}{7}\)
d: \(=\dfrac{-8}{9}\cdot\dfrac{3}{2}+\dfrac{1}{9}\cdot\dfrac{-3}{2}=-\dfrac{3}{2}\)
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a) \(\frac{15}{16}\cdot\frac{4}{3}-\frac{1}{2}:\frac{5}{4}+3\)
\(=\frac{5}{4}-\frac{2}{5}+3\)
\(=\frac{25}{20}-\frac{8}{20}+\frac{60}{20}\)
\(=\frac{77}{20}=3\frac{17}{20}\)
b) \(\left(\frac{2}{3}-\frac{3}{8}\right):\left(\frac{3}{5}+\frac{1}{4}\right)\)
\(=\frac{7}{24}:\frac{17}{20}\)
\(=\frac{35}{102}\)
c) \(\frac{15}{8}\cdot\left(\frac{1}{3}+\frac{1}{8}\right)-\frac{3}{8}:\frac{3}{4}\)
\(=\frac{15}{8}\cdot\frac{11}{24}-\frac{1}{2}\)
\(=\frac{55}{64}-\frac{1}{2}\)
\(=\frac{23}{64}\)
d) \(\frac{20}{21}:\left(\frac{4}{5}-\frac{1}{10}\right)+\frac{13}{15}:\frac{5}{26}\)
\(=\frac{20}{21}:\frac{7}{10}+\frac{52}{15}\)
\(=\frac{200}{147}+\frac{52}{15}\)
\(=4\frac{608}{735}\)
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Lời giải:
$\frac{-3}{8}.\frac{2}{15}+\frac{-3}{8}.\frac{13}{15}+1\frac{3}{8}$
$=\frac{-3}{8}(\frac{2}{15}+\frac{13}{15})+1+\frac{3}{8}$
$=\frac{-3}{8}.\frac{15}{15}+1+\frac{3}{8}=\frac{-3}{8}+1+\frac{3}{8}=1$
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Làm 1 câu
10/3...>...1/3
Mấy câu ssu tự quy đồng hay gì gì đấy!
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a) 4/15 x 2016/2018+ 4/15 x 3/2018- 4/15 x 1/2018
= 4/15 x (2016/2018 + 3/2018 - 1/2018)
= 4/15 x (\(1\frac{1}{2018}\)-1/2018)
=4/15 x 1
= 4/15
b) 8/15 x 8 - 2 x 8/15+3 x 8/15+ 8/15
= 8/15 x ( 8 - 2 + 3 + 1)
= 8/15 x 10
= 80/15 => \(5\frac{1}{3}\)
Mấy cái kia mình lười làm phân số nên mình chỉ viết rõ hỗn số thôi, bạn thông cảm nha. Chúc bạn học giỏi <3
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a) \(\dfrac{1}{3}-\dfrac{1}{3}\times\left(2-\dfrac{3}{5}\right)\\ =\dfrac{1}{3}-\dfrac{1}{3}\times\dfrac{7}{5}\\ =\dfrac{1}{3}-\dfrac{7}{15}\\ =\dfrac{5}{15}-\dfrac{7}{15}\\ =-\dfrac{2}{15}\)
b) \(\dfrac{1}{9}-\dfrac{5}{15}+\dfrac{8}{9}-\dfrac{10}{15}+0,5\\ =\left(\dfrac{1}{9}+\dfrac{8}{9}\right)-\left(\dfrac{5}{15}+\dfrac{10}{15}\right)+0,5\\ =\dfrac{9}{9}-\dfrac{15}{15}+0,5\\ =1-1+0,5\\ =0,5\)
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Tính nhẩm rồi điền kết quả vào chỗ trống.
14 - 1 = 13 15 - 4 = 11 17 - 2 = 15 15 - 3 = 12
15 - 1 = 14 19 - 8 = 11 16 - 2 = 14 15 - 2 = 13
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Phương pháp giải:
Trừ nhẩm các số rồi điền kết quả vào chỗ trống.
Lời giải chi tiết:
a)
15 − 6 = 9 15 − 7 = 8
15 − 8 = 7 15 − 9 = 6
16 − 7 = 9 16 − 8 = 8
16 − 9 = 7 17 − 8 = 9
17 − 9 = 8 18 − 9 = 9
b)
18 − 8 − 1 = 9 18 − 9 = 9
15 − 5 − 2 = 8 15 − 7 = 8
16 − 6 − 3 = 7 16 − 9 = 7
1/3 +8/15 : 3/15
= 1/3 + 8/15 x 15/3
= 1/3 + 8/3
= 9/3
= 3
1/3 +8/15 : 3/15
= 1/3 + 8/15 x 15/3
= 1/3 + 8/3
= 9/3
= 3