= 0,01247764673 :v

0.01247764672:)

`1,4+1,7-3=0,1`

a,\(5.2^2\)\(-18:3^2\)

\(=5.4-18:9\)

\(=20-2\)

\(=18\)

b, \(\text{17.85+15.17-120}\)

\(=17.\left(85+15\right)\)\(-120\)

= \(17.100-120\)

\(=1700-120\)

\(=1580\)

c, \(2^3\)\(.17-2^3\)\(.14\)

= \(2^3\)\(.\left(17-14\right)\)

\(=8.3\)

\(=24\)

Hok tốt !

Bài 1: 

a: Ta có: 8,5<3,5x<15

mà x là số nguyên

nên \(3,5x\in\left\{10,5;14\right\}\)

hay \(x\in\left\{3;4\right\}\)

b: Ta có: \(\left(3-\dfrac{1}{3}x\right):2+1.5=3\)

=>(3-1/3x):2=1,5

=>3-1/3x=3

=>x=0

a: \(\dfrac{-3}{25}\cdot\dfrac{4}{17}\cdot\dfrac{5}{-3}\cdot\dfrac{17}{2}=\dfrac{4}{17}\cdot\dfrac{17}{2}\cdot\dfrac{3}{25}\cdot\dfrac{5}{3}=2\cdot\dfrac{1}{5}=\dfrac{2}{5}\)

b: \(=-\dfrac{8}{15}\cdot\dfrac{13}{16}\cdot\dfrac{30}{13}=\dfrac{-8}{15}\cdot\dfrac{15}{8}=-1\)

c: \(=\dfrac{3}{11}\left(\dfrac{2}{9}\cdot\dfrac{-8}{33}+\dfrac{7}{9}\right)=\dfrac{3}{11}\cdot\dfrac{215}{297}=\dfrac{2015}{1089}\)

a)\(3.5^2-16:2^2\)

=\(3.25-16:4\)

=\(75-4=71\)

b)\(2^3.17-2^3.14\)

=\(8.17-8.14\)

\(=8\left(17-14\right)\)

\(=8.3=24\)

c)\(15.141+59.15\)

=\(15\left(141+59\right)\)

\(=15.200\)=3000

d)17.85+15.17-120

\(=17\left(85+15\right)-120\)

=\(17.100-120\)

=\(170-120=50\)

e)\(20+[30-\left(5-1\right)^2]\)

\(=20+[30-\left(4\right)^2]\)

\(=20+\left(30-16\right)\)

\(=20+14=34\)

3.17+3.17+3.17+.....+3.17=17.(3+3+3+...3)(100 số hạng 3)

                                         =7.3.100=21.100=2100

Bài này dễ mà em

cảm ơn anh

2³.17-14+2³.3²

=8.17-14+8.9

=136-14+72

=122+72

=194

2³x17-14+2³x3²

=8x17-14+8x9

=136-14+72

=194

2³.17-14+2³.3²

=8.17-14+8.9

=136-14+72

=122+72

=194

3,17 + 3,17 + 3.17 + .... + 3,17

= 3,17 x 100

= 317

5100 nha bạn