Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a: \(\frac{5}{11}\times\frac{7}{25}+\frac{15}{11}\times\frac15\)
\(=\frac{7}{11\times5}+\frac{3}{11}=\frac{7+3\times5}{11\times5}=\frac{22}{55}=\frac25\)
b: \(\frac37\times\frac{25}{19}-\frac17\times\frac{18}{19}\)
\(=\frac{75}{7\times19}-\frac{18}{7\times19}=\frac{57}{7\times19}=\frac37\)
Tính bằng cách thuận tiện nhất:
9/4 x 15/11 + 3/4 : 11/7 - 3/4 x 8/11
[Lưu ý trình bày cách làm ra!]
Ta có: \(\frac94\times\frac{15}{11}+\frac34:\frac{11}{7}-\frac34\times\frac{8}{11}\)
\(=\frac34\times\frac{45}{11}+\frac34\times\frac{7}{11}-\frac34\times\frac{8}{11}\)
\(=\frac34\times\left(\frac{45}{11}+\frac{7}{11}-\frac{8}{11}\right)=\frac34\times\frac{44}{11}=3\)
\(\dfrac{9}{4}\times\dfrac{15}{11}+\dfrac{3}{4}:\dfrac{11}{7}-\dfrac{3}{4}\times\dfrac{8}{11}\)
\(=\dfrac{3}{4}\times3\times\dfrac{15}{11}+\dfrac{3}{4}\times\dfrac{7}{11}-\dfrac{3}{4}\times\dfrac{8}{11}\)
\(=\dfrac{3}{4}\times\dfrac{45}{11}+\dfrac{3}{4}\times\dfrac{7}{11}-\dfrac{3}{4}\times\dfrac{8}{11}\)
\(=\dfrac{3}{4}\times\left(\dfrac{45}{11}+\dfrac{7}{11}-\dfrac{8}{11}\right)\)
\(=\dfrac{3}{4}\times4\)
\(=3\)
`9/4xx15/11+3/4:11/7-3/4xx8/11`
`=3/4xx15/11xx3+3/4xx7/11-3/4xx8/11`
`=3/4xx45/11+3/4xx7/11-3/4xx8/11`
`=3/4xx(45/11+7/11-8/11)`
`=3/4xx4`
`=3`
\(a,\dfrac{5}{13}\times\dfrac{4}{15}\times13=\dfrac{5\times4\times13}{13\times5\times3}=\dfrac{4}{3}\\ b,\left(\dfrac{3}{7}+\dfrac{5}{2}\right)\times\dfrac{7}{5}=\dfrac{3}{7}\times\dfrac{7}{5}+\dfrac{5}{2}\times\dfrac{7}{5}=\dfrac{3}{5}+\dfrac{7}{2}=\dfrac{6}{10}+\dfrac{35}{10}=\dfrac{41}{10}\\ c,\dfrac{1}{5}\times\dfrac{11}{18}+\dfrac{11}{18}\times\dfrac{3}{5}=\dfrac{11}{18}\times\left(\dfrac{1}{5}+\dfrac{3}{5}\right)=\dfrac{11}{18}\times\dfrac{4}{5}=\dfrac{22}{45}\)
a: \(245\times11+11\times365\)
=11x(245+365)
=11x610
=6710
b: \(78\times75+75\times89+75\times123\)
\(=75\times\left(78+89+123\right)\)
=75x290
=21750
c: \(2\times250\times50\times8\)
=2x50x250x8
=100x2000
=200000
d: (76:7)x4
=76x4:7
=304/7
e: (372x15)x9
=5580x9
=50220
f: (56x23x4):7
=56:7x23x4
=8x92
=736
`a)17/7-3/8+4/7-3/5`
`=(17/7+4/7)-(3/8+3/5)`
`=21/7-(15/40+24/40)=3-39/40=120/40-39/40=81/40`
`b)15/11xx2001/2005-3/11xx2001/2005-1/11xx2001/2005`
`=2001/2005xx(15/11-3/11-1/11)`
`=2001/2005xx11/11`
`=2001/2005`