Rút gọn
a) (x+1)(3-x)(x-2)2
b) 9x(1-x)+(3x-2)(3x+2)
Những câu hỏi liên quan
2 tháng 10 2021 lúc 19:27
1. Rút gọn
a, A=(4x+3y)2 + (4x-3y)2
b,B=(x-23)-(x+2)3
c,C=(x+2y)2+2.(x+2y) (x-2y) + (x-2y)2
2. Tìm x
a, x2+12x+36=0
b,16x2-8x+1=0
c,x3+3x2+3x+1=0
2a) pt <=> (x + 6)^2 = 0
<=> x = -6
b) pt <=> (4x - 1)^2 = 0
<=> x = 1/4
c) pt<=> (x + 1)^3 = 0
<=> x = -1
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Bài 1:
a: Ta có: \(A=\left(4x+3y\right)^2+\left(4x-3y\right)^2\)
\(=16x^2+24xy+9y^2+16x^2-24xy+9y^2\)
\(=32x^2+18y^2\)
b: Ta có: \(B=\left(x-2\right)^3-\left(x+2\right)^3\)
\(=x^3-6x^2+12x-8-x^3-6x^2-12x-8\)
\(=-12x^2-24\)
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2 tháng 10 2021 lúc 19:58
1. Rút gọn
a, A=(4x+3y)2 + (4x-3y)2
b,B=(x-23)-(x+2)3
c,C=(x+2y)2+2.(x+2y) (x-2y) + (x-2y)2
2. Tìm x
a, x2+12x+36=0
b,16x2-8x+1=0
c,x3+3x2+3x+1=0
Bài 2:
a: Ta có: \(x^2+12x+36=0\)
\(\Leftrightarrow x+6=0\)
hay x=-6
b: Ta có: \(16x^2-8x+1=0\)
\(\Leftrightarrow4x-1=0\)
hay \(x=\dfrac{1}{4}\)
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Bài 1:
a: Ta có: \(A=\left(4x+3y\right)^2+\left(4x-3y\right)^2\)
\(=16x^2+24xy+9y^2+16x^2-24xy+9y^2\)
\(=32x^2+18y^2\)
b: Ta có: \(B=\left(x-2\right)^3-\left(x+2\right)^3\)
\(=x^3-6x^2+12x-8-x^3-6x^2-12x-8\)
\(=-12x^2-24\)
c: Ta có: \(C=\left(x+2y\right)^2+2\left(x+2y\right)\left(x-2y\right)+\left(x-2y\right)^2\)
\(=\left(x+2y+x-2y\right)^2\)
\(=4x^2\)
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Bài1:Rút gọn
a,(4x-5)(3x+2)-(7-3x)(x+2)
b,(-2x+1)(x-5)-3(x-2)(x+1)
c,(x^2-7)(x-5)+(3x^2+5)(2x-4)
d,(x^2+3x-2)(x+4)-4x(x-5)
Bài2:Tìm xbiết
a,(x-4)(x+3)-(x+1)(x-5)=8
b,(3x-2)(x+1)-3x(x+7)=13
c,(x+5)(x-5)-x(x+2)=9
d,(x-1)(x^2+x+1)-x(x^2-3)=1
2:
a: =>x^2+3x-4x-12-(x^2-5x+x-5)=8
=>x^2-x-12-x^2+4x+5=8
=>3x-7=8
=>3x=15
=>x=5
b: =>3x^2+3x-2x-2-3x^2-21x=13
=>-20x=15
=>x=-3/4
c: =>x^2-25-x^2-2x=9
=>-2x=25+9=34
=>x=-17
d: =>x^3-1-x^3+3x=1
=>3x-1=1
=>3x=2
=>x=2/3
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Rút gọn
A=x(5x-3)-x^2(x-1)+x(x^2-62)-10+3x B=x(x^2+x+1)-x^2(x+1)-x+5
C=-3xy(-x+5y)+5y^2(3x-2y)+2(5y^2-3/2x^2y-2)
D=(3-x-6y)(x^2+2xy+4y^2)-3(x^3-8y^3+10)
\(A=5x^2-3x-x^3+x^2+x^3-62x-10+3x\\ A=6x^2-62x-10\\ B=x^3+x^2+x-x^3-x^2-x+5=5\\ C=3x^2y-15xy^2+15xy^2-10y^3+10y^2-3x^2y-4=-4\)
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b: Ta có: \(B=x\left(x^2+x+1\right)-x^2\left(x+1\right)-x+5\)
\(=x^3+x^2+x-x^3-x^2-x+5\)
=5
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Bài 1: Rút gọn
a)(x+9)(x-9)-x2
b)(10x-1)(10x+1)-(10x-1)2
c)(a+2b+3)(2a-2b-3)+(b-2c)2
d)(x-1)(x-2)-(x-2)(x+2)
a) (x+9)(x-9)-x2=x2-81-x2=-81
b) (10x-1)(10x+1)-(10x-1)2=100x2-1-100x2+20x-1=20x-2
d) (x-1)(x-2)-(x-2)(x+2)=x2-3x+2-x2+4=-3x+6
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20 tháng 12 2022 lúc 21:53
Rút gọn
a)\(\dfrac{x}{x+1}+\dfrac{1}{x-1}-\dfrac{2x}{1-x^2}\)
b)\(\dfrac{x}{x-2}-\dfrac{4x}{x^2-4}-\dfrac{2}{x+2}\)
c)\(\dfrac{2x^2-3x-9}{x^2-9}-\dfrac{x}{x+3}-\dfrac{x+3}{3-x}\)
d)\(\dfrac{x+3}{x-2}+\dfrac{x+2}{1-x}-\dfrac{4x-x^2}{x^2-3x+2}\)
giúp mik vs
cảm ơn <3
a: \(=\dfrac{x^2-x+x+1+2x}{\left(x-1\right)\left(x+1\right)}=\dfrac{\left(x+1\right)^2}{\left(x-1\right)\left(x+1\right)}=\dfrac{x+1}{x-1}\)
b: \(=\dfrac{x^2+2x-4x-2x+4}{\left(x-2\right)\left(x+2\right)}=\dfrac{x^2-4x+4}{\left(x-2\right)\left(x+2\right)}=\dfrac{x-2}{x+2}\)
c: \(=\dfrac{2x^2-3x-9-x^2+3x+x^2+6x+9}{\left(x-3\right)\left(x+3\right)}\)
\(=\dfrac{2x^2+6x}{\left(x-3\right)\left(x+3\right)}=\dfrac{2x}{x-3}\)
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15 tháng 11 2021 lúc 20:36
Rút gọn
a) \(\dfrac{x^5-2x^4+2x^3-4x^2-3x+6}{x+4}\)
b) \(\dfrac{x^4-4x^2+3}{x^4+6x^2-7}\)
c) \(\dfrac{x^4+x^3-x-1}{x^4+x^3+2x^2+x+1}\)
\(a,=\dfrac{x^4\left(x-2\right)+2x^2\left(x-2\right)-3\left(x-2\right)}{x+4}\\ =\dfrac{\left(x-2\right)\left(x^4+2x^2-3\right)}{x+4}\\ =\dfrac{\left(x-2\right)\left(x^4-x^2+3x^2-3\right)}{x+4}\\ =\dfrac{\left(x-2\right)\left(x-1\right)\left(x^2+3\right)}{x+4}\)
\(b,=\dfrac{x^4-3x^2-x^2+3}{x^4-x^2+7x^2-7}=\dfrac{\left(x^2-3\right)\left(x^2-1\right)}{\left(x^2+7\right)\left(x^2-1\right)}=\dfrac{x^2-3}{x^2+7}\\ c,=\dfrac{\left(x^3-1\right)\left(x+1\right)}{x^2\left(x^2+x+1\right)+\left(x^2+x+1\right)}\\ =\dfrac{\left(x-1\right)\left(x^2+x+1\right)\left(x+1\right)}{\left(x^2+1\right)\left(x^2+x+1\right)}=\dfrac{x^2-1}{x^2+1}\)
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Bài 1: Rút Gọn
a)(x+7)(x-7)-x2
b)(5x-1)(5x+1)-(25x2+1)
c)(4x+1)(4x-1)-(4x-1)2
d)(3x-5)2-(3x+5)(3x-5)
a) \(=x^2-49-x^2\) \(=-49\)
b) \(=25x^2-1-25x^2-1\) \(=-2\)
c) \(=16x^2-1-16x^2+8x-1\) \(=8x-2\)
d) \(=9x^2-30x+25-9x^2+25\) \(=50-30x\)
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bài 1: rút gọn bthuca.dfrac{a+sqrt{a}}{sqrt{a}} b.dfrac{sqrt{left(x-3right)^2}}{3-x}b2: rút gọna.dfrac{sqrt{9x^2-6x+1}}{9x^2-1} b.4-x-sqrt{4-4x+x^2} c.sqrt{4x^2-4xtext{x^2 +2*x-3 0}}-sqrt{4x^2+4x+1}
Đọc tiếp
bài 1: rút gọn bthuc
a.\(\dfrac{a+\sqrt{a}}{\sqrt{a}}\) b.\(\dfrac{\sqrt{\left(x-3\right)^2}}{3-x}\)
b2: rút gọn
a.\(\dfrac{\sqrt{9x^2-6x+1}}{9x^2-1}\) b.4-x-\(\sqrt{4-4x+x^2}\) c.\(\sqrt{4x^2-4x\text{x^2 +2*x-3 >0}}-\sqrt{4x^2+4x+1}\)
Bài 1:
a) \(\dfrac{a+\sqrt{a}}{\sqrt{a}}=\sqrt{a}+1\)
b) \(\dfrac{\sqrt{\left(x-3\right)^2}}{3-x}=\dfrac{\left|x-3\right|}{3-x}=\pm1\)
Bài 2:
a) \(\dfrac{\sqrt{9x^2-6x+1}}{9x^2-1}=\dfrac{\left|3x-1\right|}{\left(3x-1\right)\left(3x+1\right)}=\pm\dfrac{1}{3x+1}\)
b) \(4-x-\sqrt{x^2-4x+4}=4-x-\left|x-2\right|=\left[{}\begin{matrix}6-2x\left(x\ge2\right)\\2\left(x< 2\right)\end{matrix}\right.\)
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