\(2^3.17+70.2^3+2^3.13\)

\(=2^3.\left(17+70+13\right)\)

\(=2^3.100\)

\(=8.100\)

\(=800.\)

2³. 17 + 70 . 2³ + 2³ . 13

= 8 . 17 + 70 . 8 + 8 . 13

= 8 . ( 17 + 70 + 13 )

= 8 . 100

= 800

có ai giúp mình với

1/

a, 24 - {12 -[(-10)-(-2)]}

=24-{12-(-8)}

=24-20

=4

b,\(\frac{2}{3}\)+\(\frac{1}{3}\).(\(\frac{-2}{3}\)+\(\frac{5}{6}\)):\(\frac{2}{3}\)

=\(\frac{2}{3}\)+\(\frac{1}{3}\).(\(\frac{-4}{6}\)+\(\frac{5}{6}\)):\(\frac{2}{3}\)

=\(\frac{2}{3}\)+\(\frac{1}{3}\).\(\frac{1}{6}\).\(\frac{3}{2}\)

=\(\frac{2}{3}\)+\(\frac{1}{18}\).\(\frac{3}{2}\)

=\(\frac{2}{3}\)+\(\frac{1}{6}\).\(\frac{1}{2}\)

=\(\frac{2}{3}\)+\(\frac{1}{12}\)

=\(\frac{8}{12}\)+\(\frac{1}{12}\)

=\(\frac{9}{12}\)=\(\frac{3}{4}\)

Câu a:

\(\frac27\) + \(\frac{-3}{8}\) + \(\frac{11}{7}\) + \(\frac17\) + \(\frac{5}{-8}\)

= (\(\frac27+\frac{11}{7}+\frac17\)) -(\(\frac38\) + \(\frac58\))

= (\(\frac{13}{7}+\frac17\)) - \(\frac88\)

= \(\frac{14}{7}-1\)

= 2 - 1

= 1

Câu b:

\(\frac{3}{17}+\frac{-5}{13}+\frac{-18}{35}+\frac{14}{17}+\frac{17}{-35}+\frac{-8}{13}\)

= (\(\frac{3}{17}+\frac{14}{17}\)) - (\(\frac{5}{13}\) + \(\frac{8}{13}\)) - (\(\frac{18}{35}+\frac{17}{35}\))

= \(\frac{17}{17}-\frac{18}{18}-\) \(\frac{35}{35}\)

= 1 - 1 - 1

= 0 - 1

= -1

7) \(\dfrac{-5}{17}+\dfrac{3}{17}\le\dfrac{x}{17}\le\dfrac{13}{17}+\dfrac{-11}{17}\)

\(\Rightarrow\dfrac{-2}{17}\le\dfrac{x}{17}\le\dfrac{2}{17}\)

\(\Rightarrow-2\le x\le2\)

\(\Rightarrow x\in\left\{-2;-1;0;1;2\right\}\)

8) \(\dfrac{2}{3}\left(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{1}{3}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)\)

\(\Rightarrow\dfrac{2}{3}\left(\dfrac{6}{12}+\dfrac{9}{12}-\dfrac{4}{12}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{6}{12}-\dfrac{2}{12}\right)\)

\(\Rightarrow\dfrac{2}{3}\cdot\dfrac{11}{12}\le\dfrac{x}{18}\le\dfrac{7}{3}\cdot\dfrac{4}{12}\)

\(\Rightarrow\dfrac{22}{36}\le\dfrac{x}{18}\le\dfrac{28}{36}\)

\(\Rightarrow\dfrac{11}{18}\le\dfrac{x}{18}\le\dfrac{14}{18}\)

\(\Rightarrow x\in\left\{11;12;13;14\right\}\)

8) \(\dfrac{2}{3}\left(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{1}{3}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)\\ \dfrac{2}{3}\left(\dfrac{6}{12}+\dfrac{9}{12}-\dfrac{4}{12}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{3}{6}-\dfrac{1}{6}\right)\\ \dfrac{2}{3}.\dfrac{11}{12}\le\dfrac{x}{18}\le\dfrac{7}{3}.\dfrac{2}{6}\\ \dfrac{11}{18}\le\dfrac{x}{18}\le\dfrac{14}{18}\\ \Rightarrow11\le x\le14\\ \Rightarrow x\in\left\{11;12;13;14\right\}\)

Kết quả bằng 0

a)\(\frac{-1}{3}.\frac{141}{17}-13.\frac{-1}{17}\)

\(=\frac{141}{3}.\frac{-1}{17}-13.\frac{-1}{17}\)

\(=47.\frac{-1}{17}-13.\frac{-1}{3}\)

\(=\frac{-1}{17}.\left(47-13\right)\)

\(=\frac{-1}{17}.33=....\)(tự tính)

\(a,\)\(\frac{-1}{3}.\frac{141}{17}-13.\frac{-1}{7}\)

\(=\frac{-1.141}{3.17}+13.\frac{1}{17}\)

\(=\frac{-141}{17}.\frac{1}{7}+13.\frac{1}{7}\)

\(=\frac{1}{7}\left(-47+13\right)\)

\(=\frac{-34}{7}\)

\(b,\)\(\frac{-9}{16}.\frac{13}{3}-\left(-\frac{3}{4}\right)^2.\frac{19}{3}\)

\(=\left(\frac{3}{4}\right)^2.\frac{-13}{3}-\left(-\frac{9}{16}\right).\frac{19}{3}\)

\(=\frac{9}{16}.\frac{-13}{3}+\frac{9}{16}.\frac{19}{3}\)

\(=\frac{9}{16}\left(\frac{-13}{3}+\frac{19}{3}\right)=\frac{9}{16}.2=\frac{9}{8}\)

Ta có:

\(\left(\right. \frac{13 \frac{2}{9} - 15 \frac{2}{3}}{18 \frac{3}{7} - 17 \frac{1}{4}} \cdot \frac{30^{2} - 5^{4}}{25 - 12 \cdot 5^{2}} \left.\right) \cdot x = \frac{\frac{2}{11} + \frac{3}{13} + \frac{4}{15} + \frac{5}{17}}{4 \frac{1}{11} + \frac{5}{13} + \frac{9}{15} + \frac{13}{17}}\)

Bước 1: Đổi hỗn số về phân số

• \(13 \frac{2}{9} = \frac{119}{9}\),
• \(15 \frac{2}{3} = \frac{47}{3}\),
• \(18 \frac{3}{7} = \frac{129}{7}\),
• \(17 \frac{1}{4} = \frac{69}{4}\)

Bước 2: Tính toán từng phần

Ta có:

\(\frac{119}{9} - \frac{47}{3} = \frac{119 - 141}{9} = \frac{- 22}{9}\) \(\frac{129}{7} - \frac{69}{4} = \frac{516 - 483}{28} = \frac{33}{28}\) \(30^{2} - 5^{4} = 900 - 625 = 275\) \(25 - 12 \cdot 25 = 25 - 300 = - 275\)

Khi đó:

\(\left(\right. \frac{- 22}{9} \div \frac{33}{28} \cdot \frac{275}{- 275} \left.\right) = \left(\right. \frac{- 22}{9} \cdot \frac{28}{33} \cdot \left(\right. - 1 \left.\right) \left.\right) = \frac{616}{297}\)

Bước 3: Tính vế phải

Tử số:

\(\frac{2}{11} + \frac{3}{13} + \frac{4}{15} + \frac{5}{17} = \frac{35494}{36465}\)

Mẫu số:

\(4 \frac{1}{11} + \frac{5}{13} + \frac{9}{15} + \frac{13}{17} = \frac{149645}{36465}\)

→ Vế phải:

\(\frac{35494}{36465} \div \frac{149645}{36465} = \frac{35494}{149645}\)

Bước 4: Giải phương trình

\(\frac{616}{297} \cdot x = \frac{35494}{149645} \Rightarrow x = \frac{35494}{149645} \cdot \frac{297}{616} = \frac{813}{7118}\)

Vậy:

\(\boxed{x = \frac{813}{7118}}\)

hỉu không =]]]