Đáp án:
$\begin{array}{l}
a)\dfrac{{{{43}^2} - {{11}^2}}}{{36,{5^2} - 27,{5^2}}}\\
= \dfrac{{\left( {43 + 11} \right)\left( {43 - 11} \right)}}{{\left( {36,5 - 27,5} \right)\left( {36,5 + 27,5} \right)}}\\
= \dfrac{{54.32}}{{9.64}}\\
= 3\\
b)\dfrac{{{{97}^3} + {{83}^3}}}{{180}} - 97.83\\
= \dfrac{{\left( {97 + 83} \right)\left( {{{97}^2} - 97.83 + {{83}^2}} \right)}}{{180}} - 97.83\\
= {97^2} - 97.83 + {83^2} - 97.83\\
= {\left( {97 - 83} \right)^2}\\
= {14^2}\\
= 196\\
c)A = x\left( {2x - y} \right) - z\left( {y - 2x} \right)\\
= \left( {2x - y} \right).\left( {x + z} \right)\\
= \left( {2.1,2 - 1,4} \right).\left( {1,2 + 1,8} \right)\\
= 1.3\\
= 3\\
d)B = \left( {x - 1} \right){x^2} - 4x\left( {x - 1} \right) + 4\left( {x - 1} \right)\\
= \left( {x - 1} \right)\left( {{x^2} - 4x + 4} \right)\\
= \left( {x - 1} \right){\left( {x - 2} \right)^2}\\
= \left( {3 - 1} \right){\left( {3 - 2} \right)^2}\\
= 2.1\\
= 2
\end{array}$
