\(a/4x\left(x-3\right)-3x\left(2+x\right)\\ =4x.x-4x.3-3x.2-3x.x\\ =4x^2-12x-6x-3x^2\\ =x^2-18x\\ b/2x\left(5x+2\right)+\left(2x-3\right)\left(3x-1\right)\\ =2x.5x+2x.2+2x.3x-2x.1-3.3x+3.1\\ =10x^2+4x+6x^2-2x-9x+3\\ =16x^2-7x+3\)

a) 3x(x + 2) + 4x(-2x + 3) + (2x - 3)(3x + 1)

= 3x² + 6x - 8x² + 12x + 6x² + 2x - 9x - 3

= (3x² - 8x² + 6x²) + (6x + 12x + 2x - 9x) - 3

= x³ + 11x - 3

b) (x² + 1)(x² - x + 2) - (x² - 1)(x² + x - 2)

= x⁴ - x³ + 3x² - x + 2 - x⁴ - x³ + 3x² + x - 2

= (x⁴ - x⁴) + (-x³ - x³) + (3x² + 3x²) + (-x + x) + (2 - 2)

= -2x³ + 6x²

c) (-2x - 3)² + (3x + 2)² + (4x + 1)

= 4x² + 12x + 9 + 9x² + 12x + 4 + 4x + 1 

= (4x² + 9x²) + (12x + 12x + 4x) + (9 + 4 + 1)

= 13x² + 28x + 14

Phần b) = 3

sao bạn ko làm hẳn ra cho bạn ý

1. Thu gọn:

a) 5x. (x-3) - x. (5x+1)

= 5x² - 15x - 5x² - x = -16x

b) -3x. (x-1) - x. (x+1) + 4x. (x-2)

= -3x² + 3x - x² - x + 4x² - 8x

= -6x

Thu gọn:

(x-1)^2 - (x+2)(x-2)

4x(x-3) -3x(2+x)

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

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

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

\(=-2x+5\)

\(4x\left(x-3\right)-3x\left(2+x\right)\)

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

\(=x^2-18x\)

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

\(=10x^2+4x+6x^2-11x+3\)

\(=16x^2-7x+3\)

F(\(x\)) = -2\(x\)⁴ + 3\(x^3\) - 4\(x\) + 2\(x^4\) - \(x^2\) - 3\(x^3\) - \(x\) + 1

F(\(x\)) = ( -2\(x^4\)+2\(x^4\)) + (3\(x^3\) - 3\(x^3\)) -(4\(x\) + \(x\)) + 1

F(\(x\)) = 0 + 0 - 5\(x\) + 1

F(\(x\)) = - 5\(x\) + 1

\(f\left(x\right)=-2x^4+3x^3-4x+2x^4-x^2-3x^3-x+1\)

\(f\left(x\right)=-2x^4+2x^4+3x^3-3x^3-4x-x-x^2+1\)

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

1. Thu gọn biểu thức - Hoc24 làm rồi mà bạn?

1.

a) \(=x^2-6x+9+3x^2-15x=4x^2-21x+9\)

b) \(=9x^2+12x+4-x^2+9=8x^2+12x+13\)

2.

a) \(\Leftrightarrow x^2+8x+16-x^2+4-5=0\\ \Leftrightarrow8x=-15\\ \Leftrightarrow x=-\dfrac{15}{8}\)

b) \(\Leftrightarrow9x^2-6x+1-8x^2+12x-2x+3-5-x^2=0\\ \Leftrightarrow4x=1\\ \Leftrightarrow x=\dfrac{1}{4}\)

1,a,=x2−6x+8+3x2−15x=4x2−21x+8b,=9x2+12x+4−x2+9=8x2+12x+132,a,⇔x2+8x+16−x2+4=5⇔8x=−15⇔x=−158b,⇔9x2−6x+1−8x2−2x+12x+3−x2=5⇔4x=1⇔x=14

a, \(4x\left(x-3\right)-3x\left(2+x\right)=4x^2-12x-6x^2-3x^2=-5x^2-12x\)

b, \(2x\left(5x+2\right)+\left(2x-3\right)\left(3x-1\right)=10x^2+4x+6x^2-11x+3\)

\(=16x^2-7x+3\)

c, \(\left(x-1\right)^2-\left(x+2\right)\left(x-2\right)=x^2-2x+1-x^2+4=-2x+5\)

d, \(\left(1+2x\right)+2\left(1+2x\right)\left(x-1\right)+\left(x-1\right)^2\)

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

\(=x^2+2+2\left(-x-1+2x^2\right)=x^2+2-2x-2+4x^2=5x^2-2x\)