\(\left\{{}\begin{matrix}x\left(2x-2y+1\right)=y\\y+2\sqrt{1-x-2x^2}=2\left(1+y\right)^2\end{matrix}\right.\)

a) \(\dfrac{1}{2\left(\sqrt{x}-1\right)}.\left(\dfrac{x^2-8\sqrt{x}}{x+2\sqrt{x}+4}+1\right)-\dfrac{x-\sqrt{x}-1}{2\sqrt{x}}\)

rút gọn hộ mình vs mn

Mark the letter A, B, C or D to indicate the word/phrases SIMILAR in meaning to the underlined word(s) in each of the following questions.

Jim's decided to buy a phonograph even though they are now redundant.

A. old-fashioned

B. reproduced

C. unnecessary

D. expensive