a.\(\sqrt{72}+2\sqrt{50}-3\sqrt{32}=6\sqrt{2}+10\sqrt{2}-12\sqrt{2}=4\sqrt{2}\)

b.= \(\sqrt{\left(x+2\right)^2}+\sqrt{\left(5-x\right)^2}=x+2+5-x=7\)

A = \(2^{101}-1\)

\(=\dfrac{47.25}{25.94}=\dfrac{47}{94}=\dfrac{1}{2}\)

Bn đánh máy nhanh nhỉ ? 

x = -1 ; y = 1 

\(7^8.2^8=14^8\)

Mik ở Bình Định :(( 

\(\left(x+3\right)^2-2< x^2+10-\left(4-5x\right)\)  \(\Leftrightarrow x^2+6x+7< x^2+5x+6\)

\(\Leftrightarrow x+1< 0\Leftrightarrow x< -1\) . Có 2 số là no p/t \(\left(-\dfrac{7}{2};-2\right)\)

\(\left|x\right|=3\Rightarrow x=\pm3\) 

Ta có : \(x=3;y=-2;D=3^3.\left(-2\right)-3.3.\left(-2\right)^2+2.3.\left(-2\right)-2018=-2120\)

\(x=-3;y=-2;D=\left(-3\right)^3.\left(-2\right)-3.\left(-3\right).\left(-2\right)^2+2.\left(-3\right).\left(-2\right)-2018=-1916\)

Hay ! Sâu sắc !