Question

giúp tuiiiii

Answer 1

câu 3,4 đề số 2 mn 

Answer 2

Answer 3

Answer 4

Đề 3: 

Bài 1: 

a) Ta có: \(-\dfrac{5}{9}+\left(-\dfrac{1}{6}\right)\cdot\dfrac{7}{3}+2\dfrac{1}{18}\)

\(=\dfrac{-5}{9}+\dfrac{-7}{18}+\dfrac{37}{18}\)

\(=\dfrac{-5}{9}+\dfrac{15}{9}=\dfrac{10}{9}\)

Answer 5

Đề 3: 

Bài 1: 

b) Ta có: \(-\dfrac{3}{4}+25\%:\left(10\dfrac{3}{10}-9\dfrac{4}{5}\right)-\left(-\dfrac{1}{2}\right)^2\)

\(=\dfrac{-3}{4}+\dfrac{1}{4}:\left(\dfrac{103}{10}-\dfrac{49}{5}\right)-\dfrac{1}{4}\)

\(=-1+\dfrac{1}{4}:\left(\dfrac{103}{10}-\dfrac{98}{10}\right)\)

\(=-1+\dfrac{1}{4}:\dfrac{1}{2}\)

\(=-1+\dfrac{1}{4}\cdot2=-1+\dfrac{1}{2}=-\dfrac{1}{2}\)

Answer 6

Đề 3: 

Bài 1: 

c) Ta có: \(\dfrac{29\cdot18-29\cdot7}{28\cdot33+33}\)

\(=\dfrac{29\cdot\left(18-7\right)}{33\left(28+1\right)}\)

\(=\dfrac{29\cdot11}{33\cdot29}=\dfrac{1}{3}\)

Answer 7

Đề 3: 

Bài 2: 

a) Ta có: \(\dfrac{x-2}{8}=\dfrac{-1}{2}\)

\(\Leftrightarrow x-2=-4\)

hay x=-2

Vậy: x=-2

Answer 8

Đề 3: 

Bài 2: 

b) Ta có: \(\left(x:\dfrac{1}{4}+\dfrac{3}{2}\right)\cdot\dfrac{2}{7}=\dfrac{-1}{7}\)

\(\Leftrightarrow\left(4x+\dfrac{3}{2}\right)=\dfrac{-1}{7}:\dfrac{2}{7}=\dfrac{-1}{7}\cdot\dfrac{7}{2}=\dfrac{-1}{2}\)

\(\Leftrightarrow4x=-\dfrac{1}{2}-\dfrac{3}{2}=-2\)

hay \(x=-\dfrac{1}{2}\)

Vậy: \(x=-\dfrac{1}{2}\)

Answer 9

Câu 3:

(8 1/3.-9/23-8 17/51.14/23).3/5≤a≤(2/5-2/3+4/15):102

                            -5≤a≤0 (bạn tự tính phép tính từng dãy nhá)

⇒a ∈ {-5;-4;-3;-2;-1;0}