Bài 1

A= (x-2)(2x-1)-2x(x+3)=2x²-x-4x+2-2x²-6x=-11x+2

Bài 1:

a) \(A=\left(x-2\right)\left(2x-1\right)-2x\left(x+3\right)\)

\(A=2x^2-x-4x+2-2x^2-6x\)

\(A=-11x+2\)

b) \(B=\left(3x-2\right)\left(2x+1\right)-\left(6x-1\right)\left(x+2\right)\)

\(B=6x^2+3x-4x-2-6x^2-12x+x+2\)

\(B=-12x\)

c) \(C=6x\left(2x+3\right)-\left(4x-1\right)\left(3x-2\right)\)

\(C=12x^2+18x-12x^2+8x+3x-2\)

\(C=29x-2\)

d) \(D=\left(2x+3\right)\left(5x-2\right)+\left(x+4\right)\left(2x-1\right)-6x\left(2x-3\right)\)

\(D=10x^2-4x+15x-6+2x^2-x+8x-4-12x^2+18x\)

\(D=36x-10\)

Tao không biết

Lưu lê thanh hạ rảnh lên à bạn ???

\(\left(6x+1\right)^2-2\left(6x+1\right)\left(6x-1\right)+\left(6x-1\right)^2\)

\(=\left(6x+1+6x-1\right)^2\)

\(=36x^2\)

\(A=\left(2x+3\right)\left(4x^2-6x+9\right)-2\left(4x^2-1\right)\)

\(=8x^3-12x^2+18x+12x^2-18x+27-8x^2+2\)

\(=8x^3-8x^2+29\)

ta có 

\(A=\left(2x+3\right)\left(4x^2-6x+9\right)-2\left(4x^2-1\right)\)

\(A=8x^3-12x^2+18x+12x^2-18x+27-8x^2+2\)

\(A=8x^3-8x^2+29\)

a, (4x-3)(3x+2)-(6x+1)(2x-5)+1

=12x²-8x-9x+6-12x²+30x-2x+5+1

=11x+12

b, (3x+4)²+(4x-1)²+(2+5x)(2-5x)

=9x²+24x+16+16x²-8x+1+4-25x²

=16x+21

c, (2x+1)(4x²2x+1)+(2-3x)(4+6x+9x²)-9

=8x³+1+8-27x³-9

=-19x³

swingrock có thể giải thik rõ hơn đc ko ạ

\(A=\left(2x-3\right)\left(4x^2-6x+9\right)-2\left(4x^3-1\right)\)

\(A=8x^3-12x^2+18x-12x^2+18x-27-8x^3+2\)

\(A=\left(8x^3-8x^3\right)+\left(-12x^2-12x^2\right)+\left(18x+18x\right)+\left(-27+2\right)\)

\(A=-24x^2+36x-25\)

\(a,\left(6x+1\right)\left(x+2\right)-2x\left(3x-5\right)\)

\(=6x^2+12x+x+2-6x^2+10x\)

\(=23x+2\)

a) (6x + 1)(x + 2) - 2x(3x - 5)

= 6x² + 12x + x + 2 - 6x² + 10x

= (6x² - 6x²) + (12x + x + 10x) + 2

= 23x + 2

b) (2x - 1)² - (2x - 3)(2x + 3)

= 4x² - 4x + 1 - 4x² + 9

= (4x² - 4x²) - 4x + (1 + 9)

= -4x + 10

c) (2x - 3)³  - (3x  + 1)(5 - 4x) - 16x²

= 8x³ - 36x² + 54x - 15x + 12x² - 5 + 4x - 16x²

= 8x³ - (36x² - 12x² + 16x²) + (54x - 15x + 4x) - 5

= 8x³ - 40x² + 43x - 5

d) (3x + 2) - (x - 5) - x(3x - 13)

= 3x  + 2 - x + 5 - 3x² + 13x

= (3x - x + 13x) + (2 + 5) - 3x²

= 15x + 7 - 3x²

\(=8x^3-27-8x^3+50=23\)

\(\left(6x+1\right)^2+\left(6x-1\right)^2-2\left(1+6x\right)\left(6x-1\right)\)

\(=\left(6x+1\right)^2-2\left(6x+1\right)\left(6x-1\right)+\left(6x-1\right)^2\)

\(=\left(6x+1-6x+1\right)^2\)

\(=4\)

\(x\left(2x^2-3\right)-x^2\left(5x+1\right)+x^2\)

\(=2x^3-3x-5x^3-x^2+x^2\)

\(=\left(2x^3-5x^3\right)+\left(x^2-x^2\right)-3x\)

\(=-3x^3-3x\)

\(3x\left(x-2\right)-5x\left(1-x\right)-8\left(x^2-3\right)\)

\(=3x^2-6x-5x+5x^2-8x^2+24\)

\(=\left(3x^2+5x^2-8x^2\right)-\left(6x+5x\right)+24\)

\(=-11x+24\)