Bài 1:

\(a.8,32+14,76+5,24=8,32+\left(14,76+5,24\right)\)

\(=8,32+20=28,32\)

\(b,16,88+9,76+3,12=\left(16,88+3,12\right)+9,76\)

\(=20+9,76=29,76\)

\(c,\left(\dfrac{2}{5}+\dfrac{7}{9}\right)+\dfrac{3}{5}=\left(\dfrac{2}{5}+\dfrac{3}{5}\right)+\dfrac{7}{9}\)

\(=1+\dfrac{7}{9}=\dfrac{16}{9}\)

\(d,\dfrac{19}{11}+\left(\dfrac{8}{13}+\dfrac{3}{11}\right)\)

\(=\left(\dfrac{19}{11}+\dfrac{3}{11}\right)+\dfrac{8}{13}=\dfrac{22}{11}+\dfrac{8}{13}\)

\(=2+\dfrac{8}{13}=\dfrac{34}{13}\)

Ko làm bài ah

16,88 + 9,76 + 3,12

= (16,88 + 3,12) + 9,76

= 20 + 9,76

= 29,76

a: =6^2-15*2

=36-30=6

b: =3*25+15*4-3

=72+60

=132

c: =25*2+5

=50+5

=55

d: =5+12=17

e: =7^2(15-5)=49*10=490

f: =4^3*125-125:25

=1000-5

=995

dấu này là dấu gì vậy bạn:                           |

64 . 52 + 37 . 52 - 2 . 26

= 64 . 52 + 37 . 52 - 52

=52 (64+37-1)

=52.100

=5200

a)=9*3-26

   =27-26

   =1

b)=125*100-25*100

   =12500-2500

   =10000

64 X 52 + 37 X 52 - 2 X 26

= 64 X 52 + 37 X 52 - 52

= 52 X ( 64 + 37 - 1)

= 52 X 100

= 5200

 64 x 52 + 37 x 52 - 2 x 26

=64 x 52 + 37 x 52 - 52 x 1

=52 x ( 64 + 37 -1 )

=52 x 100

=5200

tk nhé

B1:

a) = (8/15 + 7/15) + (7/4 + 5/4)

    = 15/15 + 12/4

    = 1 + 3

    = 4

b) = (16,88 + 3/12) + 9,76

     = 20 + 9,76

     = 29,76

c) = (17,16 + 82,84) + 72,84

    = 100 + 72,84

    = 172,84

B2:

2/3 + 4/5 = 10/15 + 12/15 = 22/15

a) \(\frac{8}{15}+\frac{7}{4}+\frac{7}{15}+\frac{5}{4}\)

\(=\left(\frac{8}{15}+\frac{7}{15}\right)+\left(\frac{7}{4}+\frac{5}{4}\right)\)

\(=\frac{15}{15}+\frac{12}{4}\)

\(=1+3=4\)

b) \(16,88+9,76+3,12\)

\(=\left(16,88+3,12\right)+9,76\)

\(=20+9,76=29,76\)

c) \(72,84+17,16+82,84\)

\(=\left(82,84+17,16\right)+72,84\)

\(=100+72,84=172,84\)

\(\frac{2}{3}+\frac{4}{5}=\frac{10}{15}+\frac{12}{15}=\frac{22}{15}\)