khó hiểu

viếtlaji đề đi

Mình viết đúng rồi mà .!!!

1) Does the queen often wear a crown ? No , she doesn't . She usually wears a hat .

2) Does the wine come from oranges ? No it doesn't  . It comes from grapes

1.Does the queen often wear a crown?No,she doesn't.She usually wears a hat.

2.Does the wine come from oranges?No ,it doesn't.It comes from grapes.

=1 bạn nhé'

= 1 nha bn :))

đề là dì

ĐKXĐ : \(\hept{\begin{cases}x\ge0\\y\ge0\end{cases}}\)

Ta có :

\(\frac{x\sqrt{x}+y\sqrt{y}}{\sqrt{x}+\sqrt{y}}-\left(\sqrt{x}-\sqrt{y}\right)^2\)

\(=\frac{x\sqrt{x}+y\sqrt{y}-\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)}{\sqrt{x}+\sqrt{y}}\)

\(=\frac{x\sqrt{x}+y\sqrt{y}-\left(\sqrt{x}-\sqrt{y}\right)\left(x-y\right)}{\sqrt{x}+\sqrt{y}}\)

\(=\frac{x\sqrt{x}+y\sqrt{y}-\left(x\sqrt{x}-y\sqrt{x}-x\sqrt{y}+y\sqrt{y}\right)}{\sqrt{x}+\sqrt{y}}\)

\(=\frac{x\sqrt{x}+y\sqrt{y}-x\sqrt{x}-y\sqrt{y}+y\sqrt{x}+x\sqrt{y}}{\sqrt{x}+\sqrt{y}}\)

\(=\frac{\sqrt{xy}\left(\sqrt{y}+\sqrt{x}\right)}{\sqrt{x}+\sqrt{y}}=\sqrt{xy}\)

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đề khó hiểu quá

2x2 là 2 nhân 2 hay 2 xờ 2

2x²  

Đề bị lỗi 

a) Ta có:

\(A\left(x\right)=x^3-30x^2-31x+1\)

\(A\left(x\right)=x^3-31x^2+x^2-31x+1\)

\(A\left(x\right)=\left(x^3-31x^2\right)+\left(x^2-31x\right)+1\)

\(A\left(x\right)=x^2.\left(x-31\right)+x.\left(x-31\right)+1\)

\(A\left(x\right)=\left(x-31\right).\left(x^2+x\right)+1\)

+ Thay \(x=31\) vào biểu thức \(A\left(x\right)\) ta được:

\(A\left(x\right)=\left(31-31\right).\left(31^2+31\right)+1\)

\(A\left(x\right)=0.992+1\)

\(A\left(x\right)=0+1\)

\(A\left(x\right)=1.\)

Vậy giá trị của biểu thức \(A\left(x\right)\) là \(1\) tại \(x=31.\)

a) \(-0.8\sqrt{\left(-0.125\right)^2}=-0.8\left|-0.125\right|=-0.8\times0.125=0,1\)

b) \(\sqrt{\left(-2\right)^6}=\sqrt{2^6}=\sqrt{\left(2^3\right)^2}=\left|8\right|=8\)