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\(\frac{4}{5}.\frac{3}{7}+\frac{4}{5}.\frac{6}{7}-\frac{4}{5}.\frac{4}{14}\)
\(=\frac{4}{5}.\left(\frac{3}{7}+\frac{6}{7}-\frac{4}{14}\right)\)
\(=\frac{4}{5}.1\)
\(=\frac{4}{5}\)
b)1/2*2/3*3/4*4/5*5/6*6/7*7/8*8/9*9/10
=1x2x3x4x5x6x7x8x9
2x3x4x5x6x7x8x9x10
= 1
10
`1/7+5/6+4/7+3/6+2/7+4/6`
`=(1/7 + 4/7 + 2/7 )+(5/6 + 3/6 +4/6)`
`= 7/7 + 12/6`
`=1+2`
`=3`
`1/7+5/6+4/7+3/6+2/7+4/6`
`=(1/7+4/7+2/7)+(5/6+3/6+4/6)`
`=7/7+12/6`
`=1+2`
`=3`
\(\frac{3}{4}x\frac{4}{5}:\frac{3}{5}x\frac{6}{7}:\frac{1}{7}x\frac{5}{6}\)\(=\)\(\frac{3}{4}x\frac{4}{5}x\frac{5}{3}x\frac{6}{7}x\frac{7}{1}x\frac{5}{6}\)\(=\)\(\frac{3x4x5x6x7x5}{4x5x3x7x1x6}\)\(=\)\(\frac{\left(3\right)x\left(4\right)x\left(5\right)x\left(6\right)x\left(7\right)x5}{\left(3\right)x\left(4\right)x\left(5\right)x\left(6\right)x\left(7\right)x1}\)\(=\)\(\frac{5}{1}\)\(=\)\(5\).
(1/2+1/3+1/4+1/5+1/6+1/7)−(1/3+1/4+1/5+1/6+1/7+1/8)
= (1/2+1/8 )+(1/4+1/6 )+(1/6+1/4)−(1/3+1/7 )-(1/5 + 1/5 )
= 1/10 +1/10 +1/10 +1/10 -1/10
= 4/10 = 2/5
k mk na <3
1/2 + ( 1/3 - 1/3 ) + ( 1/4 - 1/4 ) + ( 1/5 -1/5 ) + ( 1/6 - 1/6 ) + ( 1/7 - 1/7 ) + 1/8
= 1/2 + 0 + 1/8
= 5/8
32/21
=32/21