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22 tháng 9 2019

a) \(43x^3y^3-32x^2y^2\)

\(=x^2y^2\left(43xy-32\right)\)

b) \(ax-bx+ab-x^2\)

\(=\left(ax+ab\right)-\left(bx+x^2\right)\)

\(=a\left(b+x\right)-x\left(b+x\right)\)

\(=\left(a-x\right)\left(b+x\right)\)

c) \(12a^2b-18ab^2-30b^2\)

\(=6b\left(2a^2-3ab-5b\right)\)

d) \(27a^2\left(b-1\right)-9a^3\left(1-b\right)\)

\(=27a^2\left(b-1\right)+9a^3\left(b-1\right)\)

\(=\left(27a^2+9a^3\right)\left(b-1\right)\)

\(=9a^2\left(b-1\right)\left(a+3\right)\)

25 tháng 11 2017

a,\(\dfrac{9a^2-16b^2}{4b-3a}=\dfrac{\left(3a-4b\right)\left(3a+4b\right)}{\text{4b-3a}}=-3a-4b\)

b,\(\dfrac{25a^2-30ab+9b^2}{3b-5a}=\dfrac{\left(5a-3b\right)^2}{3b-5a}=3b-5a\)

c,\(\dfrac{27a^3-27a^2+9a-1}{9a^2-6a+1}=\dfrac{27a^3-9a^2-18a^2+6a+3a-1}{9a^2-6a+1}=\dfrac{\left(3a-1\right)\left(9a^2-6a+1\right)}{9a^2-6a+1}=3a-1\)

24 tháng 8 2019

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

22 tháng 7 2016

27a2b2-18ab+3=3(9a2b2-6ab+1)=3(3ab-1)2

18 tháng 8 2020

cảm ơn bạn nha

a) Ta có: 10(x-y)-8y(y-x)

\(=10\left(x-y\right)+8y\left(x-y\right)\)

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

d) Ta có: \(x^2y-x^3-9y+9x\)

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

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

\(=\left(y-x\right)\left(x-3\right)\left(x+3\right)\)

e) Ta có: \(2x+2y-x^2-xy\)

\(=2\left(x+y\right)-x\left(x+y\right)\)

\(=\left(x+y\right)\left(2-x\right)\)

f) Ta có: \(x^2-25+y^2+2xy\)

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

\(=\left(x+y-5\right)\left(x+y+5\right)\)

g) Ta có: \(x^2-2x-4y^2-4y\)

\(=\left(x-2y\right)\left(x+2y\right)-2\left(x+2y\right)\)

\(=\left(x+2y\right)\left(x-2y-2\right)\)

h) Ta có: \(x^2\left(x-1\right)+16\left(1-x\right)\)

\(=x^2\left(x-1\right)-16\left(x-1\right)\)

\(=\left(x-1\right)\left(x^2-16\right)\)

\(=\left(x-1\right)\left(x-4\right)\left(x+4\right)\)

23 tháng 10 2017

ta gọi 

ab=0,5 (a+b)

​​\(x = {-b \pm \sqrt{b^2-4ac} \over 2a} ax+bx=67 kết quả =67\)

a) A= x^2 - 6x + 5

A=x^2-6x+9-4

A=(x-3)^2-4>hoặc= -4

Pmin =-4 <=> x-3=0 <=> x=3

P/s máy mình lag nên ko sủ dụng được cồn thức

a) Ta có: \(4\left(2-x\right)^2+xy-2y\)

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

\(=\left(x-2\right)\left[4\left(x-2\right)+y\right]\)

\(=\left(x-2\right)\left(4x-8+y\right)\)

b) Ta có: \(3a^2x-3a^2y+abx-aby\)

\(=3a^2\left(x-y\right)+ab\left(x-y\right)\)

\(=\left(x-y\right)\left(3a^2+ab\right)\)

\(=a\left(x-y\right)\left(3a+b\right)\)

c) Ta có: \(x\left(x-y\right)^3-y\left(y-x\right)^2-y^2\left(x-y\right)\)

\(=x\left(x-y\right)^3-y\left(x-y\right)^2-y^2\left(x-y\right)\)

\(=\left(x-y\right)\left[x\left(x-y\right)^2-y\left(x-y\right)-y^2\right]\)

\(=\left(x-y\right)\left[x\left(x^2-2xy+y^2\right)-yx+y^2-y^2\right]\)

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

d) Ta có: \(2ax^3+6ax^2+6ax+18a\)

\(=2ax^2\left(x+3\right)+6a\left(x+3\right)\)

\(=\left(x+3\right)\left(2ax^3+6a\right)\)

\(=2a\left(x+3\right)\left(x^3+3\right)\)

e) Ta có: \(x^2y-xy^2-3x+3y\)

\(=xy\left(x-y\right)-3\left(x-y\right)\)

\(=\left(x-y\right)\left(xy-3\right)\)