a)P= 15+45x+33x^2-55x^3

a: \(P=\left(5x-1-5x-4\right)^2=\left(-3\right)^2=9\)

b: \(Q=\left(x+y\right)^3-3xy\left(x+y\right)=x^3+y^3\)

c: \(=\dfrac{\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)}{2}\)

\(=\dfrac{\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)}{2}\)

\(=\dfrac{\left(5^8-1\right)\left(5^8+1\right)\left(5^{16}+1\right)}{2}\)

\(=\dfrac{5^{32}-1}{2}\)

A = (x - 1)(x + 3) - (x - 2)(5x - 4)

A = x²  + 2x - 3 - 5x² + 14x - 8

A = -4x² + 16x - 11

B = (3a - 2b)(9a² + 6ab - 4b²)

B = 27a³ + 18a²b - 12ab² - 18a²b - 12ab² + 8b³

B = 27a³ -24ab² + 8b³

C = (x - 1)(x + 1) - (2x - 3)(4 - 5x)

C = x² - 1 - 8x + 10x + 12 - 15x

C = x² - 13x + 11

câu 1 bạn phá hết ra

câu 2 bạn làm theo hằng đẳng thức A^2 + 2AB + B^2 = (A+B)^2

Bài 2 

a. (x-2y)2 =2x-4y

b. (2x^2 +3)2 =4x^2+6

c. (x-2) (x^2+2x+4) = x^3-8 (hằng đẳng thức)

d. (2x-1)3 = 6x-3

 Xin lỗi mik chỉ lm ổn bài 2 thôi!

$(x-2y)^2$

$=x^2-2\cdot x\cdot 2y+(2y)^2$

$=x^2-4xy+4y^2$

$(2x^2+3)^2$

$=(2x^2)^2+2\cdot2x^2\cdot3+3^2$

$=4x^4+12x^2+9$

$(x-2)(x^2+2x+4)$

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

$=x^3+2x^2+4x-2x^2-4x-8$

$=x^3-8$

$(2x-1)^3$

$=(2x)^3-3(2x)^2\cdot1+3\cdot2x\cdot1^2-1^3$

$=8x^3-12x^2+6x-1$

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

\(=36x^2+12x+1+36x^2-12x+1-72x^2+2\)

\(=4\)

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

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

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

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

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

\(=-11x+24\)