\(\dfrac{0.5+0.\left(3\right)-0.1\left(6\right)}{2.5+1.\left(6\right)-0.8\left(3\right)}\)

\(=\dfrac{\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{6}}{\dfrac{5}{2}+\dfrac{5}{3}-\dfrac{5}{6}}=\dfrac{1}{5}\)

Đặt GTBT là A, ta có:

A=0,5+0,(3)−0,1(6)2,5+1,(6)−0,8(3) 

A=12 +13 −16 52 +53 −56  

A=12 +13 −16 5(12 +13 −16 ) =15 

bạn tự điền mấy cái dấu gach p/s nha

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chúc bạn học tốt

Đặt GTBT là A, ta có:

A=0,5+0,(3)−0,1(6)2,5+1,(6)−0,8(3)

A=12+13−1652+53−56

A=12+13−165(12+13−16)=15

\(=\dfrac{1}{5}\)

1,(279)=142/111

2,(1485)=217/101

1. a) -0,35 = -7/20 ; b) 1,14 = 57/50

  c) 2,108 = 527/250 ; -0,725 = -29/40

2. a) 0,2(3) = 0,2 + 0,0(3) = 0,2 + 0,3. 0,(1) = 0,2 + 0,3.1/9 = 1/5 + 1/30 = 7/30 

  b 1,4(51) = 1,4 + 0,0(51) = 7/5 + 5,1. 0,(01) = 7/5 + 5,1. 1/99 = 7/5 + 17/330 = 479/330

  c) -2,(412) = -2 - 0,(412) = -2 - 412. 0,(001) = -2 - 412. 1/999 = -2 - 412/999 = -2410/999

d) 3,1(45) = 3,1 + 0,0(45) = 3,1 + 4,5. 0,(01) = 3,1 + 4,5 . 1/99 = 3,1 + 1/22 = 173/55

3. Ta có: -2,(6).x = 0,1(6)

=> [-2 - 0,(1).6].x = (0,1 + 0,6. 0,(1)]

=> (-2 - 2/3)x = 0,1 + 1/15

=> -8/3x = 1/6

=>  x = 1/6 : (-8/3)

=> x = -1/16

0,5+0,(3)+0,1(6)/2,5+0,1(6)+0,8(3)

=0,5+1/3+1/6/2,5+1/6+5/6

=1/3,5=2/7

k mk nha

\(\frac{0,5+\frac{1}{3}-\frac{1}{6}}{2,5+\frac{5}{3}-\frac{5}{6}}\)

= \(\frac{\frac{3}{6}+\frac{2}{6}-\frac{1}{6}}{\frac{15}{6}+\frac{10}{6}-\frac{5}{6}}\)

= \(\frac{\frac{4}{6}}{\frac{20}{6}}\)

= \(\frac{4}{6}:\frac{20}{6}\)

= \(\frac{2}{3}.\frac{3}{10}\)

= \(\frac{1}{5}\)