K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

21 tháng 9 2021

\(5x-2\left(x+3\right)=4\left(x-1\right)\)

\(\Rightarrow5x-2x-6=4x-4\)

\(\Rightarrow3x-6=4x-4\)

\(\Rightarrow4x-3x=-6+4\)

\(\Rightarrow x=-2\)

∫(5x+1)⋅dx(x+3)(x+2)(x−4)

=12⋅ln(x−4)+32⋅ln(x+2)−2ln(x+3)+C

Explanation:

I decomposed integrand into basic fractions,

5x+1(x+3)(x+2)(x−4)

=Ax+3+Bx+2+Cx−4

After expanding denominator,

A(x+2)(x−4)+B(x+3)(x−4)+C(x+3)(x+2)=5x+1

After setting x=−3, 7A=−14, so A=−2

After setting x=−2, −6B=−9, so B=32

After setting x=4, 42C=21, so C=12

Thus,

∫(5x+1)⋅dx(x+3)(x+2)(x−4)

=−2⋅∫dxx+3+32⋅∫dxx+2+12⋅∫dxx−4

=12⋅ln(x−4)+32⋅ln(x+2)−2ln(x+3)+C

24 tháng 8 2019

\(a,-5x\left(x-3\right)\left(2x+4\right)-\left(x+3\right)\left(x-3\right)+\left(5x-2\right)\left(3x+4\right)\)

\(=-5x\left(2x^2-x-12\right)-\left(x^2-9\right)+15x^2+20x-6x-8\)

\(=-10x^3+5x^2+60x-x^2+9+15x^2+20x-6x-8\)

\(=-10x^3+19x^2+74x+1\)

\(b,\left(4x-1\right)x\left(3x+1\right)-5x^2.x\left(x-3\right)-\left(x-4\right)x\left(x-5\right)\)\(-7\left(x^3-2x^2+x-1\right)\)

\(=\left(4x^2-x\right)\left(3x+1\right)-5x^4-15x^3-\left(x^2-4x\right)\left(x-5\right)\)\(-7x^3+14x^2-7x+7\)

\(=12x^3+x^2-x-5x^4-15x^3-x^3+9x^2+20x\)\(-7x^3+14x^2-7x+7\)

\(=-5x^4-11x^3+24x^2+12x+7\)

\(c,\left(5x-7\right)\left(x-9\right)-\left(3-x\right)\left(2-5x\right)-2x\left(x-4\right)\)

\(=5x^2-52x+63-6+17x-5x^2-2x^2+8x\)

\(=-2x^2-27x+57\)

24 tháng 8 2019

\(d,\left(5x-4\right)\left(x+5\right)-\left(x+1\right)\left(x^2-6\right)-5x+19\)

\(=5x^2+21x-20-x^3-x^2+6x+6-5x+19\)

\(=-x^3+4x^2+22x+5\)

\(e,\left(9x^2-5\right)\left(x-3\right)-3x^2\left(3x+9\right)-\left(x-5\right)\left(x+4\right)-9x^3\)

\(=9x^3-27x^2-5x+15-9x^3-27x^2-x^2+x+20-9x^3\)

\(=-9x^3-55x^2+4x+35\)

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

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

\(=-6x-3\)

a: \(\Leftrightarrow x^2\left(x+1\right)-\left(x+1\right)=0\)

\(\Leftrightarrow\left(x+1\right)^2\cdot\left(x-1\right)=0\)

=>x=-1 hoặc x=1

b: \(\Leftrightarrow x^2\left(x+1\right)-4\left(x+1\right)=0\)

\(\Leftrightarrow\left(x+1\right)\left(x-2\right)\left(x+2\right)=0\)

hay \(x\in\left\{-1;2;-2\right\}\)

c: \(x^3+x^2+4=0\)

\(\Leftrightarrow x^3+2x^2-x^2-2x+2x+4=0\)

\(\Leftrightarrow\left(x+2\right)\cdot\left(x^2-x+2\right)=0\)

=>x+2=0

hay x=-2

e: \(\Leftrightarrow x^4-2x^3-3x^3+6x^2-x^2+2x+3x-6=0\)

\(\Leftrightarrow\left(x-2\right)\left(x^3-3x^2-x+3\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(x-3\right)\left(x+1\right)\left(x-1\right)=0\)

hay \(x\in\left\{2;3;-1;1\right\}\)

d: \(\dfrac{x^4-2x^3+2x-1}{x^2-1}\)

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

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

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

23 tháng 9 2021

sao làm có 1 ý vậy bạn ơi

bucqua

26 tháng 7 2018

help me

13 tháng 9 2019

a)\(x^4+6x^3+11x^2+6x+1\)

\(=x^4+9x^2+1+6x^3+6x+2x^2\)

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

7 tháng 4 2022

1) 2x – (3 – 5x) = 4( x +3)

<=>2x-3+5x=4x+12

<=>2x-3+5x-4x-12=0

<=>3x-15=0

<=>x=5

7 tháng 4 2022

2) 5(2x-3) - 4(5x-7) =19 - 2(x+11)

<=>10x-15-20x+28=19-2x-22

<=>10x-15-20x+28-19+2x+22=0

<=>-8x+16=0

<=>x=2

26 tháng 7 2018

help me

dễ mà bạn xin 20 phút làm ra giấy nhé :))