a. \(5x-3\left\{4x-2\left[4x-3\left(5x-2\right)\right]\right\}=182\)

\(5x-3\left\{4x-2\left[4x-15x+6\right]\right\}=182\\ 5x-3\left\{4x-2\left[-11x+6\right]\right\}=182\\ 5x-3\left\{4x+22x-12\right\}=182\\ 5x-3\left\{26x-12\right\}=182\\ 5x-78x+36=182\\ -73x=146\\ x=-2\)

b. \(\left(x+1\right)\left(x+2\right)\left(x+5\right)-x^2\left(x+8\right)=27\\ \left(x^2+2x+x+2\right)\left(x+5\right)-x^3-8x^2=27\\ x^3+5x^2+2x^2+10x+x^2+5x+2x+10-x^3-8x^2=27\\ 17x+10=27\\ x=1\)

\(x-\dfrac{2}{3}=\dfrac{1}{6}\\ x=\dfrac{1}{6}+\dfrac{2}{3}\\ x=\dfrac{5}{6}\)

\(\left(1+\dfrac{2}{3}-\dfrac{1}{4}\right).\left(\dfrac{4}{5}-\dfrac{3}{4}\right)^2\\ =\dfrac{12}{12}+\dfrac{8}{12}-\dfrac{3}{12}.\dfrac{1}{400}\\ =\dfrac{17}{12}.\dfrac{1}{400}\\ =\dfrac{17}{4800}\)

\(2:\left(\dfrac{1}{2}-\dfrac{2}{3}\right)^3\\= 2:-\dfrac{1}{216}\\ =2.-216\\ =-432\)

Bài 1 :

\(A=\dfrac{2x+6}{\left(x+3\right)\left(x-2\right)}\\ ĐKXĐ:x\ne-3;x\ne2\)

\(A=\dfrac{2x+6}{\left(x+3\right)\left(x-2\right)}=0\\ \Leftrightarrow\dfrac{2x+6}{\left(x+3\right)\left(x-2\right)}=\dfrac{0}{\left(x+3\right)\left(x-2\right)}\\ \Leftrightarrow2x+6=0\\ \Leftrightarrow2x=-6\\ \Leftrightarrow x=-3\left(loại\right)\)

\(B=\dfrac{x^2-9}{x^2-6x+9}\\ ĐKXĐ:x\ne3;x\ne-3\)

\(B=\dfrac{x^2-9}{x^2-6x+9}=0\\ \Leftrightarrow\dfrac{x^2-3^2}{\left(x-3\right)^2}=0\\ \Leftrightarrow\left(x-3\right)\left(x+3\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x-3=0\\x+3=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=3\left(loại\right)\\x=-3\left(loại\right)\end{matrix}\right.\)

Đề yêu cầu gì nhỉ

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

Vậy Q không phụ thuộc vào giá trị của biến 

Bài 1 "

a. \(\left(2x-3y\right)\left(x-2y\right)=2x^2-4xy-3xy+6y^2=2x^2-7xy+6y^2\)

b. \(\left(3x+2\right)^2-\left(x-1\right)\left(2x-3\right)\\ =\left(9x^2+12x+4\right)-\left(2x^2-3x-2x+3\right)\\ =9x^2+12x+4-2x^2+3x+2x-3\\ =7x^2+17x+1\)

c. \(\left(x-2\right)^2-3\left(x-3\right)\left(x+3\right)-\left(x-2\right)\\ =x^2-4x+4-3x^2+27-x+2\\ =-2x^2-5x+33\)