nho rut gon
x^3-3x^2-x+2
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Những câu hỏi liên quan
cho A = 1/15 nhan 225/(8+2) + 3/14 nhan 196/(3x+6) (x thuoc Z; x khac -2 )
a) Rut gon A
b) Tim x thuoc Z de A thuoc Z
c) trong cac gia tri nguyen A tim gia tri lon nhat va gia tri nho nhat
rut gon (x^2-2)(1-x) + ( x+3)(x^2-3x+9)
\(\left(x^2-2\right)\left(1-x\right)+\left(x+3\right)\left(x^2-3x+9\right)\)
\(=\left(x^2-x^3-2+2x\right)+\left(x^3+3^3\right)\)
\(=x^2-x^3-2+2x+x^3+27\)
\(=\left(-x^3+x^3\right)+x^2+2x+\left(-2+27\right)\)
\(=x^2+2x+25\)
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rut gọn 2x(2 x-1)^2-3x(x+3)(x-3) -4x(x+1)^2
Ta có:
2x(2x-1)2-3x(x+3)(x-3)-4x(x+1)2
=2x(4x2-4x+1)-3x(x2-9)-4x(x2+2x+1)
=8x3-8x2+2x-3x3+27x-4x3-8x2+4x
=x3-16x2 +33x
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1) CMR: 543-54 khong la so chinh phuong
2) Tim x:
2(x-2).(x+3)-x2+4=0
3) Rut gon
a)2(x+1)2-3(x-1)2+(x+2).(5-x)
b)(3x-1)3+(3x-1)3-6x2+9
4) A= (x-5).(x+2)+3.(x-2).(x+2)-(3x-1)2+5x2
a) rut gon A
b) tinh a khi x =1/2
\(2\left(x-2\right)\left(x+3\right)-x^2+4=0\)
\(2\left(x^2+3x-2x-6\right)-x^2+4=0\)
\(2x^2+6x-4x-12-x^2+4=0\)
\(x^2+2x-8=0\)
\(x^2+4x-2x-8=0\)
\(x\left(x+4\right)-2\left(x+4\right)=0\)
\(\left(x+4\right)\left(x-2\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x+4=0\rightarrow x=\left(-4\right)\\x-2=0\rightarrow x=2\end{cases}}\)
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3/
a/ \(2\left(x+1\right)^2-3\left(x-1\right)^2+\left(x+2\right)\left(5-x\right)\)
\(=2\left(x^2+2x+1\right)-3\left(x^2-2x+1\right)+\left(5x-x^2+10-2x\right)\)
\(=2x^2+4x+2-3x^2+6x-3+5x-x^2+10-2x\)
\(=-2x^2+13x+9\)
b/ \(\left(3x-1\right)^3+\left(3x-1\right)^3-6x^2+9\)
\(=2\left(3x-1\right)^3-6x^2+9\)
\(=2\left(\left(3x\right)^3-3\left(3x\right)^2\cdot1+3\cdot3x\cdot1-1\right)-6x^2+9\)
\(=2\left(27x^3-27x^2+9x-1\right)-6x^2+9\)
\(=54x^3-54x^2+18x-2-6x^2+9\)
\(=54x^3-60x^2+18x+7\)
Số hơi dài, nên dễ tính sai -,- tính mik hay cẩu thả có j sai ibbb ạ
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2) 2.(x - 2).(x + 3) - x2 + 4 = 0
<=> x2 + 2x - 8 = 0
<=> (x - 2).(x + 4) = 0
x - 2 = 0 hoặc x + 4 = 0
x = 0 + 2 x = 0 - 4
x = 2 x = -4
=> x = 2 hoặc x = -4
3) a) 2.(x + 1)2 - 3.(x - 1)2 + (x + 2).(5 - x)
= 2.(x2 + 2x + 1) - 3.(x2 - 2x + 1) + (x + 2).(5 - x)
= 2x2 + 4x + 2 - 3x2 + 6x - 3 + (x + 2).(5 - x)
= 2x2 + 4x + 2 - 3x2 + 6x - 3 + 3x - x2 + 10
= (2x2 - 3x2 - x2) + (4x + 6x + 3x) + (2 - 3 + 10)
= -2x2 + 13x + 9
b) (3x - 1)3 + (3x - 1)3 - 6x2 + 9
= 2.(3x - 1)3 - 6x2 + 9
= 2.(27x3 - 27x2 + 9x - 1) - 6x2 + 9
= 54x3 - 54x2 + 18x - 2 - 6x2 + 9
= 54x3 + (-54x2 - 6x2) + 18x + (-2 + 9)
= 54x3 - 60x + 18x + 7
4) a) A = (x - 5).(x + 2) + 3.(x - 2).(x + 2) - (3x - 1)2 + 5x2
A = (x - 5).(x + 2) + 3.(x - 2).(x + 3) - (9x2 - 6x + 1) + 5x2
A = x2 - 3x - 10 + 3x2 - 12 - (9x2 - 6x + 1) + 5x2
A = x2 - 3x - 10 + 3x2 - 12 - 9x2 + 6x - 1 + 5x2
A = (x2 + 3x2 - 9x2 + 5x2) + (-3x + 6x) + (-10 - 12 - 1)
A = 3x - 23 (1)
b) Thay x = 1/2 vào (1), ta có:
A = 3x - 23 = 3.(1/2) - 23
= 3/2 - 23
= -43/2
A khi x = 1/2 là -43/2
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1) CMR: 543-54 khong la so chinh phuong
2) Tim x:
2(x-2).(x+3)-x2+4=0
3) Rut gon
a)2(x+1)2-3(x-1)2+(x+2).(5-x)
b)(3x-1)3+(3x-1)3-6x2+9
4) A= (x-5).(x+2)+3.(x-2).(x+2)-(3x-1)2+5x2
a) rut gon A
b) tinh a khi x =1/2
rut gon phan thức 3x^2-11xy+6y^2/x^3+3x-3xy-9y
giúp mình với ạ cần gấp lắm rùi
Rut gon A=3x^3-7x^2+5x-1 / 2x^3-x^2-4x+3
Rut gon
x^3+3X+7x^3+2x^2+5X+1
\(x^3+3x+7x^3+2x^2+5x+1\)
\(=8x^3+2x^2+8x+1\)
tham khảo nhé~
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=(x^3+7x^3)+2x^2+(3x+5x)+1
=8x^3+2x^2+8x+1
Hok tot!!!!
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7x3 + x3 + 2x2 + 5x + 3x + 1
= (7x3 + x3) + 2x2 + (5x + 3x) + 1
= 8x3 + 2x2 + 8x + 1
= 2x.(4x2 + x + 4) + 1
Chúc em học tốt!!!
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Xem thêm câu trả lời
rut gon bieu thuc a,(3x+2)^2+4x-3^2+2(5x-2)(5x+2)-75x^2
b,(x-2)^3+(2x+1)^3++2(x+2)(1-x)-9x^3+2x
a: \(\left(3x+2\right)^2+4x-3x^2+2\left(5x-2\right)\left(5x+2\right)-75x^2\)
\(=9x^2+12x+4+4x-3x^2+50x^2-8-75x^2\)
\(=-19x^2+16x-4\)
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