Xin lũi vì sự sai sót này = ((

\(\left(105-x\right):2^5=0+1\)

\(105-x=1.2^5\)

\(x=105-32\)

\(x=73\)

Hello, my name is...

B

Vì \(AE//BC\Rightarrow\widehat{EAB}=\widehat{ABC}=y=70^0\) (slt)

Ta có : \(\widehat{ABC}\widehat{+\widehat{BAC}+ACB=180^0}\)

\(\Rightarrow70^0+x+75^0=180^0\)

\(\Rightarrow x=35^0\)

Vì \(\left\{{}\begin{matrix}AE//BC\\AB\perp BC\end{matrix}\right.\)

\(\Rightarrow AE\perp AB\) tại A ( qh giữa vuông góc và song song )

\(\Rightarrow\widehat{BAE}=90^0\)

Ta có: \(\widehat{EAC}+\widehat{BAC}=\widehat{BAE}=90^0\)

\(\Rightarrow60^0+x=90^0\)

\(\Rightarrow x=30^0\)

Vì \(AE//BC\Rightarrow\widehat{EAC}=\widehat{ACB}=y=60^0\)

a) \(x=25\left(tmđk\right)\)

\(\rightarrow\sqrt{x}=5\)

Thay vào A ta có :

\(A=\dfrac{25-5+1}{5-1}=\dfrac{21}{4}\)

b) \(B=\dfrac{\left(\sqrt{x}+1\right)\left(\sqrt{x}+3\right)+2\left(\sqrt{x}-2\right)-9\sqrt{x}+3}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+3\right)}\)

\(B=\left(\dfrac{x+3\sqrt{x}+\sqrt{x}+3+2\sqrt{x}-4-9\sqrt{x}+3}{\left(\sqrt{x}+2\right)\left(\sqrt{x}+3\right)}\right)\)

\(B=\dfrac{x-3\sqrt{x}+2}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+3\right)}\)

\(B=\dfrac{\left(\sqrt{x}-2\right)\left(\sqrt{x}-1\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+3\right)}\)

\(B=\dfrac{\sqrt{x}-1}{\sqrt{x}+3}\)

a) \(\left(x-4\right)^2-\left(x-4\right)=0\)

\(\left(x-4\right)\left(x-4-1\right)=0\)

\(\left[{}\begin{matrix}x-4=0\\x-5=0\end{matrix}\right.\)

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

b) \(5x^2\left(x-7\right)+7\left(x-7\right)=0\)

\(\left(x-7\right)\left(5x^2+7\right)=0\)

\(\left[{}\begin{matrix}x-7=0\\5x^2+7=0\end{matrix}\right.\)

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

\(x=7\)

c) \(x^2\left(x-3\right)-\left(x-3\right)=0\)

\(\left(x-3\right)\left(x^2-1\right)=0\)

\(\left[{}\begin{matrix}x=3\\x=\pm1\end{matrix}\right.\)

a) \(=2\left(x-y\right)-\left(x^2-2xy+y^2\right)\)

\(=2\left(x-y\right)-\left(x-y\right)^2\)

\(=\left(x-y\right)\left(2-x+y\right)\)

\(=\sqrt{8-2\sqrt{7}}\)

\(=\sqrt{7-2\sqrt{7}+1}\)

\(=\sqrt{\left(\sqrt{7}-1\right)^2}\)

1) \(\left(x-y\right)\left(2-a\right)\)

2) \(\left(x-y\right)\left(a+b\right)\)

3) \(\left(x+y\right)\left(m-n\right)\)

4) \(\left(x+y\right)\left(2a-4\right)=2\left(x+y\right)\left(a-2\right)\)

5) \(\left(x+y\right)\left(3a-6ab\right)=3a\left(x+y\right)\left(1-2b\right)\)

6) \(\left(x-y\right)\left(5a^2+10a\right)=5a\left(x-y\right)\left(a+2\right)\)

7)\(\left(x-y\right)\left(-2ab-4a\right)=-2a\left(x-y\right)\left(b+2\right)\)

8) \(\left(x-y\right)\left(3a+2\right)\)

9) \(\left(a-b\right)\left(m-m^2\right)=m\left(a-b\right)\left(1-m\right)\)

10) \(\left(a+b\right)\left(mx-m\right)=m\left(a+b\right)\left(x-1\right)\)