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

\(\Leftrightarrow x^2-2\times\dfrac{1}{2}x+\dfrac{1}{4}=8:2\)

\(\Leftrightarrow x^2-x+\dfrac{1}{4}=4\)

\(\Leftrightarrow x\left(x-1\right)=\dfrac{15}{4}\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{15}{4}\\x-1=\dfrac{15}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{15}{4}\\x=\dfrac{19}{4}\end{matrix}\right.\)

\(2500kg=25000tạ\)

\(a,76.58+25.44+24.56=76.58+\left(25.44+24.56\right)=76.58+50=126.58\)

\(b,23.43+28.48+21.52+26.57=\left(23.43+26.57\right)+\left(28.48+21.52\right)=50+50=100\)

\(c,15.35+24.56+14.65=\left(15.35+14.65\right)+24.56=30+24.56=54.56\)

\(d,26.52+18.37+17.63=26.52+\left(18.37+17.63\right)=26.52+36=62.52\)

 Ý nghĩa :

- 220V là hiệu điện thế định mức để bóng đèn đó sáng bình thường.

- 40W là công suất định mức khi đèn sáng bình thường.

She has been out of work since last month.

\(x^2-x+\left(2\text{x}-2\right)=0\)

\(\Leftrightarrow x\left(x-1\right)+2\left(x-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\x+2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-2\end{matrix}\right.\)

D