`(2x-1/3)^2=4`

\(< =>\left[{}\begin{matrix}2x-\dfrac{1}{3}=2\\2x-\dfrac{1}{3}=-2\end{matrix}\right.\\ < =>\left[{}\begin{matrix}2x=2+\dfrac{1}{3}\\2x=-2+\dfrac{1}{3}\end{matrix}\right.\\ < =>\left[{}\begin{matrix}2x=\dfrac{7}{3}\\2x=-\dfrac{5}{3}\end{matrix}\right.\\ < =>\left[{}\begin{matrix}x=\dfrac{7}{3}:2\\x=-\dfrac{5}{3}:2\end{matrix}\right.\\ < =>\left[{}\begin{matrix}x=\dfrac{7}{3}\cdot\dfrac{1}{2}\\x=-\dfrac{5}{3}\cdot\dfrac{1}{2}\end{matrix}\right.\\ < =>\left[{}\begin{matrix}x=\dfrac{7}{6}\\x=-\dfrac{5}{6}\end{matrix}\right.\)

\(\left(2x-\dfrac{1}{3}\right)^2=4\)

\(\Rightarrow\left[{}\begin{matrix}2x-\dfrac{1}{3}=2\\2x-\dfrac{1}{3}=-2\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}2x=2+\dfrac{1}{3}\\2x=-2+\dfrac{1}{3}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}2x=\dfrac{7}{3}\\2x=-\dfrac{5}{3}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{7}{4}\\x=-\dfrac{5}{4}\end{matrix}\right.\)

\(\dfrac{4}{7}\times X=\dfrac{1}{2}\\ X=\dfrac{1}{2}:\dfrac{4}{7}=\dfrac{1}{2}\times\dfrac{7}{4}=\dfrac{7}{8}\)

\(\dfrac{7}{8}\)

a/ x+65,27=72,6

    x=72,6-65,27

     x=7,33

b/x-43,502=21,73

            x=21,73+43,502

              x=65,232

c/x.6,3=187

           x=187:6,3

           x=29,682....

d/ 1602:x=7,2

           x=1602:7,2

           x=222,5

\(X+65,27=72,6\\ X=72,6-65,27=7,33\\ ---\\ X-43,502=21,73\\ X=21,73+43,502=65,232\\ ---\\ X.6,3=187\\ X=\dfrac{187}{6,3}=\dfrac{1870}{63}\\ ---\\ 1602:X=7,2\\ X=1602:7,2=222,5\)

192 = 2.96= 2. (8.12)

Vì: 12= 8+4

Vậy ao cũ có cạnh bằng 8m

Diện tích ao cũ:

8.8 = 64(m²)

A={14;23;32;41;50}

14, 41, 23, 32, 50

25% của 120 lít bằng:

25% x 120 = 30(lít)

Đ.số: 30 lít

Chọn D

D

25% x 120 = 30(lít)

10 phút 5 giây

7 phút 35 giây + 2 phút 30 giây

= 10 phút 5 giây

Sửa đề : 3% của 6m

6 x 3% = 0,18 ( m) = 18 cm

=> Chọn C

3% của 6 = 6 . 3% = 6. 0,03=0,18(m)=18(cm)

Ý C

D. 1000 đồng

100 000 đồng x 1%

1% x 100000 = 1000 đồng

Chọn D

\(\dfrac{26^4}{\left(-13\right)^5}=\dfrac{13^4.2^4}{13^4.\left(-13\right)}=\dfrac{2^4}{-13}=-\dfrac{16}{13}\)

\(-\dfrac{16}{3}\)nhé