Thực hiện phép tính
4 2/5+2 3/7- 2 2/5 +5 4/7 đây là phép tính hỗn số giúp mình ngay nhé xin cảm ơn
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\frac{3}{5}-\frac{-7}{10}-\frac{13}{-20}=\frac{3}{5}+\frac{7}{10}+\frac{13}{20}=\frac{12}{20}+\frac{14}{20}+\frac{13}{20}=\frac{39}{20}\)
\(\frac{1}{2}+\frac{-1}{3}+\frac{1}{4}-\frac{-1}{6}=\frac{1}{2}+\frac{-1}{3}+\frac{1}{4}+\frac{1}{6}=\frac{6+(-4)+3+2}{12}=\frac{7}{12}\)
\(\frac{9}{4}.\frac{8}{27}.\frac{5}{7}=\frac{9.8.5}{4.27.7}=\frac{1.2.5}{1.3.7}=\frac{10}{21}\)
\(\frac{2}{5}.(\frac{2}{3}-\frac{1}{4})+\frac{1}{2}=\frac{2}{5}.(\frac{8}{12}-\frac{3}{12})+\frac{1}{2}=\frac{2}{5}.\frac{5}{12}+\frac{1}{2}=\frac{1}{6}+\frac{1}{2}=\frac{1}{6}+\frac{3}{6}=\frac{4}{6}=\frac{2}{3}\)
\((\frac{1}{3}-\frac{1}{6}):(\frac{1}{3}+\frac{1}{6})=(\frac{2}{6}-\frac{1}{6}):(\frac{2}{6}+\frac{1}{6})=\frac{1}{6}:\frac{3}{6}=\frac{1}{6}.\frac{6}{3}=\frac{1.6}{6.3}=\frac{1.1}{1.3}=\frac{1}{3}\)
Hok tốt
\(\frac{3}{5}.\left(\frac{5}{3}-\frac{2}{7}\right)-\left(\frac{7}{3}-\frac{3}{7}\right).\frac{3}{5}\)
\(=\frac{3}{5}.\text{[}\left(\frac{5}{3}-\frac{2}{7}\right)-\left(\frac{7}{3}-\frac{3}{7}\right)\text{]}\)
\(=\frac{3}{5}.\text{[}\frac{5}{3}-\frac{2}{7}-\frac{7}{3}+\frac{3}{7}\text{]}\)
\(=\frac{3}{5}.\text{[}\left(\frac{5}{3}-\frac{7}{3}\right)-\left(\frac{2}{7}-\frac{3}{7}\right)\text{]}\)
\(=\frac{3}{5}.\text{[}\frac{-2}{3}-\frac{-1}{7}\text{]}\)
\(=\frac{3}{5}.\left(\frac{-2}{3}+\frac{1}{7}\right)\)
\(=\frac{3}{5}.\left(\frac{-14}{21}+\frac{3}{21}\right)\)
\(=\frac{3}{5}.\frac{-11}{21}\)
\(=\frac{3.\left(-11\right)}{5.21}\)
\(=\frac{-11}{5.7}=\frac{-11}{35}\)
Chúc bạn học tốt
Bài 2:
a: 5/7-3/7x=1
=>3/7x=-2/7
hay x=-2/3
b: \(x+\dfrac{2}{3}=\dfrac{-1}{12}\cdot\dfrac{-4}{5}=\dfrac{1}{15}\)
=>x=1/15-2/3=-9/15=-3/5
c: \(x-4=\dfrac{-14}{35}:\dfrac{7}{5}=\dfrac{-14}{35}\cdot\dfrac{5}{7}=\dfrac{-70}{245}=\dfrac{-2}{7}\)
=>x=4-2/7=26/7
Giải:
a) \(2\dfrac{17}{20}-1\dfrac{15}{11}+6\dfrac{9}{20}:3\)
\(=\dfrac{57}{20}-\dfrac{26}{11}+\dfrac{129}{20}:3\)
\(=\dfrac{107}{220}+\dfrac{43}{20}\)
\(=\dfrac{29}{11}\)
b) \(4\dfrac{3}{7}:\left(\dfrac{7}{5}.4\dfrac{3}{7}\right)\)
\(=\dfrac{31}{7}:\left(\dfrac{7}{5}.\dfrac{31}{7}\right)\)
\(=\dfrac{31}{7}:\dfrac{31}{5}\)
\(=\dfrac{5}{7}\)
c) \(\left(3\dfrac{2}{9}.\dfrac{15}{23}.1\dfrac{7}{29}\right):\dfrac{5}{23}\)
\(=\left(\dfrac{29}{9}.\dfrac{15}{23}.\dfrac{36}{29}\right):\dfrac{5}{23}\)
\(=\dfrac{60}{23}:\dfrac{5}{23}\)
\(=12\)
a, =(94/7+57/13)-8.3/7
=(1222/91+399/91)-8.3/7
=1621/91-24/7
=187/13
b,=(6/1-14/5).25/8-8/5:1/4
=(30/5-14/5).25/8-8/5.4/1
=16/5.25/8-32/5
=10-32/5
=10/1-32/5
=50/5-32/5
=18/5
\(2\frac{3}{4}.\frac{1}{2}-\frac{1}{2}.\frac{3}{7}+\frac{1}{3}\)
\(=\frac{11}{4}.\frac{1}{2}-\frac{1}{2}.\frac{3}{7}+\frac{1}{3}\)
\(=\frac{11}{8}-\frac{3}{14}+\frac{1}{3}\)
\(=\frac{251}{168}\)
Bài 1 : a, thực hiện phép tính :
\(2\frac{3}{4}×\frac{1}{2}-\frac{1}{2}×\frac{3}{7}+\frac{1}{3}\)
\(=\frac{11}{4}×\frac{1}{2}-\frac{1}{2}×\frac{3}{7}+\frac{1}{3}\)
\(=\frac{1}{2}×\left(\frac{11}{4}-\frac{3}{7}\right)+\frac{1}{3}\)
\(=\frac{1}{2}×\frac{65}{28}+\frac{1}{3}\)
\(=\frac{65}{56}+\frac{1}{3}\)
\(=\frac{251}{168}\)
b , Tìm x biết :
a, 435- ( x + 16 ) = 425 : 17
435 - ( x + 16 ) = 25
x + 16 = 435 - 25
x + 16 = 410
x = 410 - 16
x = 394
Vậy x = 394
b, ( x + 3/4 ) × 7/4 = 5 - 7/6
( x + 3/4 ) × 7/4 = 23/6
x + 3/4 = 23/6 : 7/4
x + 3/4 = 23/6 × 4/7
x + 3/4 = 46/21
x = 46/21 - 3/4
x = 121/84
Vậy x = 121/84
C1:
A = \(3\frac{5}{7}+4\frac{2}{3}\)\(-\left(2\frac{5}{7}+2\frac{1}{3}\right)\)
A = \(3\frac{5}{7}+4\frac{2}{3}\)\(-2\frac{5}{7}-2\frac{1}{3}\)
A = \(3\frac{5}{7}-2\frac{5}{7}+4\frac{2}{3}-2\frac{1}{3}\)
A = \(1+2\frac{1}{3}\)
A = \(1+\frac{7}{3}\)
A = \(\frac{10}{3}\)
C2:
A = \(3\frac{5}{7}+4\frac{2}{3}\)\(-\left(2\frac{5}{7}+2\frac{1}{3}\right)\)
A = \(\frac{26}{7}+\frac{14}{3}-\frac{19}{7}-\frac{7}{3}\)
A = \(1+\frac{14}{3}-\frac{7}{3}=\frac{10}{3}\)
C1: Ta có: \(B=8\frac{1}{9}-3\frac{2}{7}+6\frac{8}{7}-3\frac{5}{7}\)
\(=8+\frac{1}{9}-\left(3+\frac{2}{7}\right)+6+\frac{8}{7}-\left(3+\frac{5}{7}\right)\)
\(=8+\frac{1}{9}-3-\frac{2}{7}+6+1+\frac{1}{7}-3-\frac{5}{7}\)
= \(\left(8-3+6+1-3\right)+\left(\frac{1}{9}-\frac{2}{7}+\frac{1}{7}-\frac{5}{7}\right)\)
\(=9+\left(\frac{-47}{63}\right)\)
\(=\frac{520}{63}\)
C2: Đổi hỗn số ra phân số rồi tính ( cj nghĩ thế )
\(4\frac{2}{5}+2\frac{3}{7}-2\frac{2}{5}+5\frac{4}{7}\)
\(=\left(4\frac{2}{5}-2\frac{2}{5}\right)+\left(2\frac{3}{7}+5\frac{4}{7}\right)\)
\(=2+8\)
=10
4 2/5 + 2 3/7 - 2 2/5 + 5 4/7
= 22/5 + 17/7 -12/5 + 39/7
= ( 22/5 - 12/5 ) + ( 17/7 + 39/7 )
= 2 + 8
= 10