1. ( the queen/often/wears/a crown? no,she/do.she/usually/wear/a hat) 2: (wine/come/from oranges? no it do. It/come/from grapes mong các bạn giúp đỡ mik
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ĐKXĐ : \(\hept{\begin{cases}x\ge0\\y\ge0\end{cases}}\)
Ta có :
\(\frac{x\sqrt{x}+y\sqrt{y}}{\sqrt{x}+\sqrt{y}}-\left(\sqrt{x}-\sqrt{y}\right)^2\)
\(=\frac{x\sqrt{x}+y\sqrt{y}-\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)}{\sqrt{x}+\sqrt{y}}\)
\(=\frac{x\sqrt{x}+y\sqrt{y}-\left(\sqrt{x}-\sqrt{y}\right)\left(x-y\right)}{\sqrt{x}+\sqrt{y}}\)
\(=\frac{x\sqrt{x}+y\sqrt{y}-\left(x\sqrt{x}-y\sqrt{x}-x\sqrt{y}+y\sqrt{y}\right)}{\sqrt{x}+\sqrt{y}}\)
\(=\frac{x\sqrt{x}+y\sqrt{y}-x\sqrt{x}-y\sqrt{y}+y\sqrt{x}+x\sqrt{y}}{\sqrt{x}+\sqrt{y}}\)
\(=\frac{\sqrt{xy}\left(\sqrt{y}+\sqrt{x}\right)}{\sqrt{x}+\sqrt{y}}=\sqrt{xy}\)
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) \(\sqrt{\left(-2\right)^6}=\sqrt{2^6}=\sqrt{\left(2^3\right)^2}=\left|8\right|=8\)
A = 165 + 215
=> A = ( 24 )5 + 215
=> A = 220 + 215
=> A = 215 ( 25 + 1 )
=> A = 215 . 33 chia hết cho 33 ( đpcm )
Ta có: 165 + 215
= (24)5 + 215
= 220 + 215
= 215.25 + 215
= 215.(25 + 1)
= 215.33
Vì 33 chia hết cho 33 nên 215.33 chia hết cho 33
Vậy 165 + 215 chia hết cho 33 (đpcm)
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.