\(2.\left(3x-1\right)\left(2-2x\right)-5x\)
\(\lrArr6x-6x^2-2+2x-5x\)
\(\lrArr-6x^2+9x-2\)
\(4.\left(2-3x\right)\left(2x+3\right)-4x^2\)
\(\lrArr4x+6-6x-9-4x^2\)
\(\lrArr-4x^2-2x-3\)
\(6.\left(2x-1\right)\left(x+1\right)+x\left(2x-5\right)\)
\(\lrArr2x^2+2-x-1+2x^2-5x\)
\(\lrArr4x^2-6x-1\)
\(8.\left(3x-1\right)\left(x+4\right)-3x\left(x-1\right)\)
\(\lrArr3x^2+12x-x-4-3x^2+3x\)
\(\lrArr14x-4\)
\(10.6x\left(2x+3\right)-\left(3x-1\right)\left(4x-1\right)\)
\(\lrArr12x^2+18x-12x^2+3x-4x+1\)
\(\lrArr17x+1\)
\(12.\left(2-5x\right)\left(3-4x\right)+x\left(2x+23\right)\)
\(\lrArr6-8x-15x+20x^2+2x^2+23x\)
\(\lrArr22x^2+6\)
\(14.-4x\left(x+3\right)\left(x-4\right)-3x\left(x^2-x+1\right)\)
\(\lrArr-4x\left(x^2-x-12\right)-3x\left(3x^2-x+1\right)\)
\(\lrArr-4x^3+4x^2+48x-3x^3+3x^2-3x\) \(\lrArr-7x^3+7x^2+45x\)
\(16.\)
\(\lrArr-2\left(2x^3-6x^2+x-3\right)+x\left(4x^2+9x+2\right)\)
\(\lrArr-4x^3+12x^2-2x+6+4x^3+9x^2+2x\)
\(\lrArr21x^2+6\)
2. \((3x - 1)(2 - 2x) - 5x\)
\(= 3x \cdot 2 + 3x \cdot (-2x) - 1 \cdot 2 - 1 \cdot (-2x) - 5x\)
\(= 6x - 6x^2 - 2 + 2x - 5x\)
\(= -6x^2 + (6x + 2x - 5x) - 2\)
\(= -6x^2 + 3x - 2\)
4. \((2x - 3)(2x + 3) - 4x^2\)
\(= (2x)^2 - 3^2 - 4x^2\)
\(=4x^2-9-4x^2=-9\)
6. \((2x - 1)(x + 1) + x(2x - 5)\)
\(= (2x^2 + 2x - x - 1) + (2x^2 - 5x)\)
\(= 2x^2 + x - 1 + 2x^2 - 5x\)
\(= (2x^2 + 2x^2) + (x - 5x) - 1\)
\(= 4x^2 - 4x - 1\)
8. \((3x - 1)(x + 4) - 3x(x - 1)\)
\(= (3x^2 + 12x - x - 4) - (3x^2 - 3x)\)
\(= 3x^2 + 11x - 4 - 3x^2 + 3x\)
\(= (3x^2 - 3x^2) + (11x + 3x) - 4\)
\(= 14x - 4\)
10. \(6x(2x + 3) - (3x - 1)(4x + 1)\)
\(= (12x^2 + 18x) - (12x^2 + 3x - 4x - 1)\)
\(= 12x^2 + 18x - (12x^2 - x - 1)\)
\(= 12x^2 + 18x - 12x^2 + x + 1\)
\(= (12x^2 - 12x^2) + (18x + x) + 1\)
\(= 19x + 1\)
12. \((2 - 5x)(3 - 4x) + x(2x + 23)\)
\(= (6 - 8x - 15x + 20x^2) + (2x^2 + 23x)\)
\(= 20x^2 - 23x + 6 + 2x^2 + 23x\)
\(= (20x^2 + 2x^2) + (-23x + 23x) + 6\)
\(= 22x^2 + 6\)
14. \(-4x(x + 3)(x - 4) - 3x(x^2 - x + 1)\)
\(= -4x(x^2 - 4x + 3x - 12) - (3x^3 - 3x^2 + 3x)\)
\(= -4x(x^2 - x - 12) - 3x^3 + 3x^2 - 3x\)
\(= -4x^3 + 4x^2 + 48x - 3x^3 + 3x^2 - 3x\)
\(= (-4x^3 - 3x^3) + (4x^2 + 3x^2) + (48x - 3x)\)
\(= -7x^3 + 7x^2 + 45x\)
16. \(-2(x - 3)(2x^2 + 1) + x(4x + 1)(x + 2)\)
\(= -2(2x^3 + x - 6x^2 - 3) + x(4x^2 + 8x + x + 2)\)
\(= -2(2x^3 - 6x^2 + x - 3) + x(4x^2 + 9x + 2)\)
\(= (-4x^3 + 12x^2 - 2x + 6) + (4x^3 + 9x^2 + 2x)\)
\(= (-4x^3 + 4x^3) + (12x^2 + 9x^2) + (-2x + 2x) + 6\)
\(= 21x^2 + 6\)
