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\(a,\frac{97^3+83^3}{180}-97.83\)
\(=\frac{\left(97+83\right)\left(97^2-97.83+83^2\right)}{180}-97.83\)
\(=\frac{180\left(97^2-97.83+83^2\right)}{180}-97.83\)
\(=97^2-97.83+83^2-97.83\)
\(=97^2+83^2-2.97.83\)
\(=\left(97-83\right)^2\)
\(=14^2=196\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(R=\frac{43^2-11^2}{\left(36,5\right)^2-\left(27,5\right)^2}\)
\(=\frac{\left(43-11\right)\left(43+11\right)}{\left(36,5-27,5\right)\left(36,5+27,5\right)}\)
\(=\frac{32.54}{9.64}\)
\(=\frac{6}{2}=3\)
Bạn viết sai đề bài rồi
\(S=\frac{97^3+83^3}{180}-97.83\)
\(=\frac{\left(97+83\right)\left(97^2-97.83+83^2\right)}{180}-97.83\)
\(=97^2-97.83+83-97.83\)
\(=\left(97-83\right)^2=14^2=196\)
Trả lời:
\(R=\frac{43^2-11^2}{36,5^2-27,5^2}\)
\(R=\frac{\left(43-11\right).\left(43+11\right)}{\left(36,5-27,5\right).\left(36,5+27,5\right)}\)
\(R=\frac{32.54}{9.64}\)
\(R=3\)
Đề bài sai bạn nhé
\(S=\frac{97^3+83^3}{180}-97.83\)
\(S=\frac{\left(97+83\right).\left(97^2-97.23+83^2\right)}{180}-97.83\)
\(S=97^2-97.83+83^2-97.83\)
\(S=97^2-2.97.83+83^2\)
\(S=\left(97-83\right)^2\)
\(S=14^2\)
\(S=196\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài 1:
\(\frac{97^3+83^3}{180}-97\cdot83=\frac{\left(97+83\right)\left(97^2-97\cdot83+83^2\right)}{180}-97\cdot83\)
\(=97^2-97\cdot83+83^2-97\cdot83=97^2-2\cdot97\cdot83+83^2\)
\(=\left(97-83\right)^2=14^2=196\)
Bài 2:
\(x^2-10x=-25\)
\(\Leftrightarrow x^2-10x+25=0\)
\(\Leftrightarrow\left(x-5\right)^2=0\)
\(\Leftrightarrow x-5=0\Leftrightarrow x=5\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Nốt câu c
\(C=\frac{97^3+83^3}{180}-97.83\)
\(=\frac{\left(97+83\right)\left(97^2-97.83+83^3\right)}{180}-97.83\)
\(=\frac{180.\left(97^2-97.83+83^2\right)}{180}-97.83\)
\(=97^2-97.83+83^2-97.83\)
\(=\left(97-83\right)^2=14^2=196\)
1.
a) \(2\left(x+3\right)-x^2-3x=0\)
⇔ \(2\left(x+3\right)-x\left(x+3\right)=0\)
⇔ \(\left(x+3\right)\left(2-x\right)=0\)
⇔ \(\left[{}\begin{matrix}x=2\\x=-3\end{matrix}\right.\)
b) \(\left(2x+1\right)^2-\left(x-1\right)^2=0\)
⇔ \(\left(2x+1-x+1\right)\left(2x+1+x-1\right)=0\)
⇔ \(3x\left(x+2\right)=0\)
⇔ \(\left[{}\begin{matrix}x=0\\x=-2\end{matrix}\right.\)
c) \(x^2-4x+3=0\)
⇔ \(x\left(x-1\right)-3\left(x-1\right)=0\)
⇔ \(\left(x-1\right)\left(x-3\right)=0\)
⇔ \(\left[{}\begin{matrix}x=1\\x=3\end{matrix}\right.\)
2, a) \(B=\left(2x+3\right)\left(4x^2-6x+9\right)-2\left(4x^3-1\right)-2x\)
⇔ \(B=8x^3+27-8x^3+2-2x=29-2x\)
Tại x = 3
Thì B = 29 - 6 = 23
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![](https://rs.olm.vn/images/avt/0.png?1311)
\(A=\dfrac{97^3+83^3}{180}-97.83\)
\(A=\dfrac{\left(97+83\right)\left(97^2-97.83+83^2\right)}{180}-97.83\)
\(A=\dfrac{180\left(97^2-97.83+83^2\right)}{180}-97.83\)
\(A=97^2-97.83+83^2-97.83\)
\(A=97^2-2.97.83+83^2\)
\(A=\left(97-83\right)^2\)
\(A=14^2\)
\(A=196\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) Ta có: \(85^2-15^2\)
\(=\left(85-15\right)\left(85+15\right)\)
\(=70\cdot100=7000\)
b) Ta có: \(93^3+21\cdot93^2+3\cdot49\cdot93+343\)
\(=93^3+3\cdot93^2\cdot7+3\cdot93+7^2+7^3\)
\(=\left(93+7\right)^3\)
\(=100^3=1000000\)
c) Ta có: \(73^2-13^2-10^2+20\cdot13\)
\(=73^2-\left(13^2+10^2-20\cdot13\right)\)
\(=73^2-\left(13^2-2\cdot13\cdot10+10^2\right)\)
\(=73^2-\left(13-10\right)^2\)
\(=73^2-3^2=\left(73-3\right)\left(73+3\right)\)
\(=70\cdot76=5320\)
a) \(85^2-15^2=\left(85-15\right)\left(85+15\right)=70.100=7000\)
b) \(93^3+21.93^2+3.49.93+343\)
\(=93^3+3.7.93^2+3.7^2.93+7^3\)
\(=\left(93+7\right)^3\)
\(=100^3=1000000\)
c) \(73^2-13^2-10^2+20.13\)
\(=73^2-\left(13^2+10^2-20.13\right)\)
\(=73^2-\left(13-10\right)^2\)
\(=73^2-3^2\)
\(=\left(73+3\right)\left(73-3\right)\)
\(=76.70=5320\)
d) Viết = Latex hộ mình
\(C=\frac{97^3+83^3}{180}-97.83\)
\(C=\frac{\left(97+83\right)\left(97^2-97.83+83^2\right)}{180}-97.83\)
\(C=\frac{180\left(97^2-97.83+83^2\right)}{180}-97.83\)
\(C=97^2-97.83+83^2-97.83\)
\(C=97^2-2.97.83+83^2\)
\(C=\left(97-83\right)^2=14^2=196\)