D = 3 { x + 1 } + 2 { x - 2 } - x + 3
E = 7 { 2 x + 1 } - 3 { x - 2 } + 5
F = { x - 2 } { x + 2 } - { x - 3 } { x + 3 } -1
G = { x - 1 } { x + 1 } - x { x - 3 } + 2
thu gọn các biểu thức trên
thu gọn các biểu thức sau:tim x:
A=(x+1)+(x+2)+(x+3)+....+(x+100)
B=(x-2)+(x-4)+...+(x-2014)
C=(1-x)+(3-x)+...+(2015-x)
D=3(x+1)+2(x-2)-x+3
E=7(2x+1)-3(x-2)+5
F=(x-1)(x+1)-x(x-3)+2
G=(x-2)(x+2)-(x-3)(x+3)-1
B1: Rút gọn biểu thức( / là giá trị tuyệt đối nha)
a) E= 3/x-5/ -5/x-7/
b) F= 2/3-x/ +3/2+x/
c)G= 2/3x-1/ -3/1-x/
B2:Tìm x
a)3/2x-1/+5=2
b) /x+3/+/x-5/=8
c) 2/3x-3/+3/2x/=/=3
d)/x+2007/+/x+2008/=3x
Rút gọn các biểu thức sau:
a) 2x(x - 7) - (x + 3)(x - 2) - (x + 4)(x - 4)
b) (2x + 5)(x - 2) - 3(x + 2)2 + (x + 1)2
c) (x + 3)(x - 3) - (x + 5)(x - 1) - (x - 4)2
d) 2x(x + 1)2 - (x - 1)3 - (x - 2)(x2 + 2x + 4)
e) (x + 5)(x - 5)(x + 2) - (x + 2)3
a) 2x( x - 7 ) - ( x + 3 )( x - 2 ) - ( x + 4 )( x - 4 )
= 2x2 - 14x - ( x2 + x - 6 ) - ( x2 - 16 )
= 2x2 - 14x - x2 - x + 6 - x2 + 16
= 22 - 15x
b) ( 2x + 5 )( x - 2 ) - 3( x + 2 )2 + ( x + 1 )2
= 2x2 + x - 10 - 3( x2 + 4x + 4 ) + x2 + 2x + 1
= 3x2 + 3x - 9 - 3x2 - 12x - 12
= -9x - 21
c) ( x + 3 )( x - 3 ) - ( x + 5 )( x - 1 ) - ( x - 4 )2
= x2 - 9 - ( x2 + 4x - 5 ) - ( x2 - 8x + 16 )
= x2 - 9 - x2 - 4x + 5 - x2 + 8x - 16
= -x2 + 4x - 20
d) 2x( x + 1 )2 - ( x - 1 )3 - ( x - 2 )( x2 + 2x + 4 )
= 2x( x2 + 2x + 1 ) - ( x3 - 3x2 + 3x - 1 ) - ( x3 - 8 )
= 2x3 + 4x2 + 2x - x3 + 3x2 - 3x + 1 - x3 + 8
= 7x2 - x + 9
e) ( x + 5 )( x - 5 )( x + 2 ) - ( x + 2 )3
= ( x2 - 25 )( x + 2 ) - ( x3 + 6x2 + 12x + 8 )
= x3 + 2x2 - 25x - 50 - x3 - 6x2 - 12x - 8
= -4x2 - 37x - 58
Rút gọn biểu thức
A. x(x - 1) + 6(x - 3)(x + 3)
B. (2 - 3x)(2 + 3x) - (x + 5)(x - 5)
C. (3x + 1 )(x +5) - (x - 1)(x + 1)
D. (2 - 3x)(2x + 3) + 6(x - 1)^2
E. x(5 - x) - (2x + 2)(3x + 2) - (x - 2)(x + 2)
F. (2 - x)(2 + x) - 2x(x - 7) + x(x + 1)
. Giúp mình với mình đang cần gấp
A)\(x\left(x-1\right)+6\left(x-3\right)\left(x+3\right)\)
\(=x^2-x+6\left(x^2-9\right)\)
\(=x^2-x+6x^2-54\)
\(=7x^2-x-54\)
F.\(\left(2-x\right)\left(2+x\right)-2x\left(x-7\right)+x\left(x+1\right)\)
\(=4-x^2-2x^2+14x+x^2+x\)
\(=-2x^2+15x+4\)
\(\left(2-3x\right)\left(2+3x\right)-\left(x+5\right)\left(x-5\right)\)
\(=4-9x^2-x^2+25\)
\(=29-10x^2\)
\(\left(3x+1\right)\left(x+5\right)-\left(x-1\right)\left(x+1\right)\)
\(=3x^2+16x+5-x^2+1\)
\(=2x^2+16x+6\)
\(\left(2-3x\right)\left(2x+3\right)+6\left(x-1\right)^2\)
\(=4x+6-6x^2-9x+6x^2-12x+6\)
\(=12-21x\)
Rút gọn các biểu thức sau:
a,(3x+1)^2-2(3x+1)(3x-5)+(3x-5)^2
b,(3x^2-y)^2
c,(3x+5)^2+(3x-5)^2-(3x+2)(3x-2)
d,2x(2x-1)^2-3x(x+3)(Õ-3)-4x(x+1)^2
e,(x-2)(x^2+2x+4)-(x+1)^2+3(x-1)(x+1)
f,(x^4-5x^2+25)(x^2+5)-(2+x^2)^2+3(1+x^2)^2
a) (3x + 1)^2 - 2(3x + 1)(3x - 5) + (3x - 5)^2
= 9x^2 + 6x + 1 - 18x^2 + 24x + 10 + 9x^2 - 30x + 25
= 36
b) (3x^2 - y)^2
= 9x^4 - 6x^2y + y^2
c) (3x + 5)^2 + (3x - 5)^2 - (3x + 2)(3x - 2)
= 9x^2 + 30x + 25 + 9x^2 - 30x + 25 - 9x^2 + 4
= 9x^2 + 54
d) 2x(2x - 1)^2 - 3x(x + 3)(x - 3) - 4x(x + 1)^2
= 8x^3 - 8x^2 + 2x - 3x^2 + 27x - 4x^3 - 8x^2 - 4x
= x^3 - 16x^2 + 25x
e) (x - 2)(x^2 + 2x + 4) - (x + 1)^2 + 3(x - 1)(x + 1)
= x^3 - 8 - x^2 - 2x - 1 + 3x^2 - 2
= x^3 + 2x^2 - 2x - 12
f) (x^4 - 5x^2 + 25)(x^2 + 5) - (2 + x^2)^2 + 3(1 + x^2)^2
= x^6 + 125 - 4 - 4x^2 - x^2 + 3 + 6x^2 + 3x^4
= x^6 + 2x^4 + 2x^2 + 124
Cho các đa thức : f(x)= 2x(x^2-3)-4(1-2x)+x^2(x-2)+(5x+3)
g(x)=-3(1-x^2)-2(x^2-2x-1)
a) Thu gọn các đa thức trên và sắp xếp theo lũy thừa giảm dần của biến
b) Tính h(x)=f(x)-g(x) và tìm nghiệm của đa thức h(x)
a) f(x) = 3x3-2x2+7x-1
g(x) = x2+4x-1
b) h(x) = 3x3-2x2+7x-1-x2-4x+1
= 3x3-3x2+3x
h(x) = 3x3-3x2+3x=0
⇒ 3(x3-x2+x)=0
⇒ x3-x2+x=0
đến đây mik ko biết làm nữa
Tìm GTLN,GTNN(nếu có) của các biểu thức sau:
a)A=-4-x^3+6x.
b)B=3x^2-5x+7
c)C=|x-3|(2-|x-3|)
d)D=(x-1)(x+5)(x^2+4x+5)
e)E=-x^2-4x-y^2+2y
f)F=(x-1)(x-3)+11
g)G=(x-3)^2+(x-2)^2
H=2000/x^2+2x+6
i)I=15/6x-x^2-14
j)M=8x+3/4x^2+1
k)K=3x^2+2x+3/x^2+1
Giúp mik đi 😀
1.Rút gọn các biểu thức
a.(2x+1) mũ 2-4x(x.5)
b)(x+3)mũ 2 - (x+1)(x-1)
c)(x-5)mũ 2 - (x+2)mũ 2
d)(x+3)mũ 2 - (x-3)mũ 2
e)2x(x+1)-(x+3)mũ 2-x mũ 2
g)(x+3)mũ 2+(x+2)mũ 2-2(x+3)(x+2)
Câu a :
\(\left(2x+1\right)^2-4x\left(x-5\right)\)
\(=4x^2+4x+1-4x^2+20\)
\(=4x+19\)
Câu b :
\(\left(x+3\right)^2-\left(x+1\right)\left(x-1\right)\)
\(=x^2+6x+9-x^2-1\)
\(=6x-8\)
Câu c :
\(\left(x-5\right)^2-\left(x+2\right)^2\)
\(=\left(x-5-x-2\right)\left(x-5+x+2\right)\)
\(=-7\left(2x-3\right)\)
\(\text{b) }\left(x+3\right)^2-\left(x+1\right)\left(x-1\right)\\ =\left(x+3\right)^2-\left(x^2-1^2\right)\\ =x^2+2\cdot x\cdot3+3^2-x^2+1\\ =\left(x^2-x^2\right)+6x+\left(9+1\right)\\ =6x+10\\ \)
\(\text{c) }\left(x-5\right)^2-\left(x+2\right)^2\\ =\left(x^2-2\cdot x\cdot5+5^2\right)-\left(x^2+2\cdot x\cdot2+2^2\right)\\ =x^2-10x+25-x^2-4x-4\\ =\left(x^2-x^2\right)-\left(10x+4x\right)+\left(25-4\right)\\ =-14x+21\\ \)
\(\text{d) }\left(x+3\right)^2-\left(x-3\right)^2\\ =\left(x^2+2\cdot x\cdot3+3^2\right)-\left(x^2-2\cdot x\cdot3+3^2\right)\\ =x^2+6x+9-x^2+6x-9\\ =\left(x^2-x^2\right)+\left(6x+6x\right)+\left(9-9\right)\\ =12x\\ \)
\(\text{e) }2x\left(x+1\right)-\left(x+3\right)^2-x^2\\ =2x^2+2x-\left(x^2+2\cdot x\cdot3+3^2\right)-x^2\\ =2x^2+2x-x^2-6x-9-x^2\\ =\left(2x^2-x^2-x^2\right)+\left(2x-6x\right)-9\\ =-4x-9\\ \)
\(\text{g) }\left(x+3\right)^2+\left(x+2\right)^2-2\left(x+3\right)\left(x+2\right)\\ =\left[\left(x+3\right)-\left(x+2\right)\right]^2\\ =\left(x+3-x-2\right)^2\\ =1^2\\ =1\\ \)
câu 1:giải các pt và bpt sau: a,17x - 5(x+3)= 2x + 5 b,3/x+2 - 5/x-2 = 11x + 23/(x+2)(x-2) c,5x + 7 ≥ 3(x-1) d,3x-1/x+1 = -2/5 e,(2x-1)(2x+1)= 4x2 + 3x + 2 f,x-3^3 -7+3x g,7x-5 < 2(4x-1)+7
a: =>17x-5x-15-2x-5=0
=>10x-20=0
=>x=2
b: =>\(\dfrac{3x-6-5x-10}{\left(x+2\right)\left(x-2\right)}=\dfrac{11x+23}{\left(x+2\right)\left(x-2\right)}\)
=>11x+23=-2x-16
=>13x=-39
=>x=-3(nhận)
c: =>5x+7>=3x-3
=>2x>=-10
=>x>=-5
d: =>5(3x-1)=-2(x+1)
=>15x-5=-2x-2
=>17x=3
=>x=3/17
e: =>4x^2-1-4x^2-3x-2=0
=>-3x-3=0
=>x=-1
g: =>7x-5-8x+2-7<0
=>-x-10<0
=>x+10>0
=>x>-10