1) `2x(3x-1)-(2x+1)(x-3)`

`=6x^2-2x-2x^2+6x-x+3`

`=4x^2+3x+3`

2) `3(x^2-3x)-(4x+2)(x-1)`

`=3x^2-9x-4x^2+4x-2x+2`

`=-x^2-7x+2`

3) `3x(x-5)-(x-2)^2-(2x+3)(2x-3)`

`=3x^2-15x-(x^2-4x+4)-(4x^2-9)`

`=3x^2-15x-x^2+4x-4-4x^2+9`

`=-2x^2-11x+5`

4) `(2x-3)^2+(2x-1)(x+4)`

`=4x^2-12x+9+2x^2+8x-x-4`

`=6x^2-5x+5`

a: Ta có: \(\left(x+5\right)^2-4x\left(2x+3\right)^2-\left(2x-1\right)\left(x+3\right)\left(x-3\right)\)

\(=x^2+10x+25-4x\left(4x^2+12x+9\right)-\left(2x-1\right)\left(x^2-9\right)\)

\(=x^2+10x+25-16x^3-48x^2-36x-2x^3+18x+x^2-9\)

\(=-18x^3-46x^2-8x+16\)

1: \(=6x^2+2x-15x-5-x^2+6x-9+4x^2+20x+25-27x^3-27x^2-9x-1\)

=-27x^3-18x^2+4x+10

2: =4x^2-1-6x^2-9x+4x+6-x^3+3x^2-3x+1+8x^3+36x^2+54x+27

=7x^3+37x^2+46x+33

5:

\(=25x^2-1-x^3-27-4x^2-16x-16-9x^2+24x-16+\left(2x-5\right)^3\)

\(=8x^3-60x^2+150-125+12x^2-x^3+8x-60\)

=7x^3-48x^2+8x-35

giúp mình với ah

a. \(A=9x^2-30x+25-4x^2+12x-9+16-4x^2\)

\(=x^2-18x+32\)

b. \(B=25x^2-70x+49-\left(4x+3\right)\left(4x^2+12x+9\right)-3x^3+9x^2+5x-15\)

\(=25x^2-70x+49-\left(16x^3+48x^2+36x-12x^2-36x-27\right)-3x^3+9x^2+5x-15\)

\(=-19x^3+-2x^2-65x+61\)

Chúc em học tốt ^^

\(a,=x^2-4-x^2+2x+3=2x-1\\ b,=x^3+3x^2-5x-15+x^2-x^3+4x-4x^2=-x-15\\ c,=2x^2+3x-10x-15-2x^2+6x+x+7=-8\\ d,=\left(2x+1+3x-1\right)^2=25x^2\)

a: A=(4x+5)^2-2*(4x+5)(4x-5)+(4x-5)^2

=(4x+5-4x+5)^2

=10^2=100

b:  B=(3x-2)^2*(3x+2)^2-2(2x+3)(2x-3)

=(9x^2-4)^2-2(4x^2-9)

=81x^4-72x^2+16-8x^2+18

=81x^4-80x^2+34

\(a,A=\left(4x-5\right)^2+\left(4x+5\right)^2+2\left(5+4x\right)\left(5-4x\right)\)

\(=\left(5-4x\right)^2 +2\left(5-4x\right)\left(4x+5\right)+\left(4x+5\right)^2\)

\(=\left(5-4x+4x+5\right)^2\)

\(=10^2\)

\(=100\)

\(b,B=\left(3x-2\right)^2\left(3x+2\right)^2-2\left(2x+3\right)\left(2x-3\right)\)

\(=\left(9x^2-4\right)^2-2\left(4x^2-9\right)\)

\(=81x^4-72x^2+16-8x^2+18\)

\(=81x^4-80x^2+34\)

#\(Urushi\)

a/\(\left(2x+1\right)^2-\left(2x+3\right)\left(2x-3\right).\)

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

\(=4x^2+4x+1-4x^2+9\)

\(=4x+10\)

b/\(4\left(x-1\right)\left(x+3\right)+5\left(2x+1\right)^2-2\left(5-3x\right)^2\)

\(=4\left(x^2+3x-x-3\right)+5\left(4x^2+4x+1\right)-2\left(25-30x+9x^2\right)\)

\(=4\left(x^2+2x-3\right)+5\left(4x^2+4x+1\right)-2\left(25-30x+9x^2\right)\)

\(=4x^2+8x-12+20x^2+20x+5-50+60x-18x^2\)

\(=6x^2+88x-57\)

mik tính toán cẩu thả lắm ạ có j sai ib ạ. Cảm ơn :3