Tính nhanh:
a, \(\frac{7}{13}\) . \(\frac{7}{15}\) - \(\frac{5}{12}\) . \(\frac{21}{39}\) + \(\frac{49}{91}\) . \(\frac{8}{15}\)
:"(( Ai làm giúp điiTính nhanh:
a, \(\frac{7}{13}\) . \(\frac{7}{15}\) - \(\frac{5}{12}\) . \(\frac{21}{39}\) + \(\frac{49}{91}\) . \(\frac{8}{15}\)
Ai trả lời giúp mk đii~~
7/13.7/15-5/12.21/39+49/91+8/15
=7/13.7/15-5/12.7/13+7/13.8/15
=7/13.(7/15-5/12+8/15)
=7/13.7/12
=49/156
7/13x7/15-5/12x21/39+49/91x8/15
=7/13x7/15-5/12x7/13+7/13x8/15
=7/13x(7/15-5/12+8/15)
=7/13x7/12
=49/156
7/13.7/15-5/12.21/39+49/91.8/15 =7/13.7/15-5/12.7/13+7/13.8/15 =7/13(7/15-5/12+8/15) =7/13.7/12 =49/156
Tính nhanh:
a,\(\frac{7}{15}\). \(\frac{7}{13}\) - \(\frac{5}{12}\) . \(\frac{21}{39}\) + \(\frac{49}{91}\) . \(\frac{8}{15}\)
Ai trả lời giúp mk đii~~
Tính nhanh:
a,\(\frac{7}{13}\cdot\frac{7}{15}-\frac{5}{12}\cdot\frac{21}{39}+\frac{49}{91}\cdot\frac{8}{15}\)
b,\(\left(\frac{12}{199}+\frac{23}{200}-\frac{34}{201}\right)\cdot\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)\)
Tính nhanh:
a,\(\frac{7}{15}\). \(\frac{7}{13}\) - \(\frac{5}{12}\) . \(\frac{21}{39}\) + \(\frac{49}{91}\) . \(\frac{8}{15}\)
Ai trả lời giúp mk đii TT TT
\(\frac{7}{13}\)×\(\frac{7}{15}\)—\(\frac{5}{12}\)×\(\frac{21}{39}\)+\(\frac{49}{91}\)×\(\frac{8}{15}\)
1. Tính nhanh
a, \(\frac{7}{13}.\frac{7}{15}-\frac{5}{12}.\frac{21}{39}+\frac{49}{91}.\frac{8}{15}\)
b, \(\left(\frac{12}{199}+\frac{23}{200}-\frac{34}{201}\right).\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)\)
c,\(\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
Tính nhanh:
a, \(\frac{7}{13}\) . \(\frac{7}{15}\) - \(\frac{5}{12}\) . \(\frac{21}{39}\) + \(\frac{49}{91}\) . \(\frac{8}{15}\)
= 7/13 x 7/3x5 - 5/3x4 x 3x7/3x13 + 7x7/7x13 x 2x4 /3x5
=1/13 x 1/5 x 1/3 x 2/1
=2/195
dấu / là đấu gạch _ của phân số đó mình không biết viết phân số trên máy tính bạn có thể chỉ mình không
Tính nhanh:
a, \(\frac{7}{13}\) . \(\frac{7}{15}\) - \(\frac{5}{12}\) . \(\frac{21}{39}\) + \(\frac{49}{91}\) . \(\frac{8}{15}\)
\(\frac{7}{13}.\frac{7}{15}-\frac{5}{12}.\frac{21}{39}+\frac{49}{91}.\frac{8}{15}\\ =\frac{7}{13}.\frac{7}{15}-\frac{5}{12}.\frac{7}{13}+\frac{7}{13}.\frac{8}{15}\\ =\frac{7}{13}\left(\frac{7}{15}+\frac{8}{15}-\frac{5}{12}\right)\\ =\frac{7}{13}\left(1-\frac{5}{12}\right)\\ =\frac{7}{13}.\frac{7}{12}\\ =\frac{49}{156}\)
Tính nhanh:
a, \(\frac{7}{13}\) . \(\frac{7}{15}\) - \(\frac{5}{12}\) . \(\frac{21}{39}\) + \(\frac{49}{91}\) . \(\frac{8}{15}\)