rút gọn
\(5X^3\) +4X\(^{^{ }2}\) - 3X.(2X\(^2\) +7X-1)
Những câu hỏi liên quan
Rút gọn các phân thức: \(\dfrac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}\)
ĐKXĐ: \(x\ne1;x\ne-\dfrac{3}{2}\)
Ta có: \(\dfrac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}=\dfrac{\left(x-1\right)^2\left(3x-1\right)}{\left(x-1\right)^2\left(2x+3\right)}=\dfrac{3x-1}{2x+3}\)
Đúng 1
Bình luận (0)
rút gọn A=(3x^3-7x^2+5x-1):(2x^3-x^2-4x+3)
Rút gọn:
\(\frac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}\)
\(\frac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}=\frac{\left(3x^3-3x^2\right)-\left(4x^2-4x\right)+\left(x-1\right)}{\left(2x^3-2x^2\right)+\left(x^2-x\right)-\left(3x-3\right)}=\frac{\left(x-1\right).\left(3x^2-4x+1\right)}{\left(x-1\right).\left(2x^2+x-3\right)}\\ \)
\(=\frac{3x^2-4x+1}{2x^2+x-3}=\frac{\left(3x^2-3x\right)-\left(x-1\right)}{\left(2x^2-2x\right)+\left(3x-3\right)}=\frac{\left(x-1\right).\left(3x-1\right)}{\left(x-1\right).\left(2x+1\right)}=\frac{3x-1}{2x+1}\)
Đúng 0
Bình luận (0)
\(\frac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}\)
\(=\frac{3x^3-3x^2-4x^2+4x+x-1}{2x^3-2x^2+x^2-x-3x+3}\)
\(=\frac{\left(3x^3-3x^2\right)-\left(4x^2-4x\right)+\left(x-1\right)}{\left(2x^3-2x^2\right)+\left(x^2-x\right)-\left(3x-3\right)}\)
\(=\frac{3x^2\left(x-1\right)-4x\left(x-1\right)+\left(x-1\right)}{2x^2\left(x-1\right)+x\left(x-1\right)-3\left(x-1\right)}\)
\(=\frac{\left(3x^2-4x+1\right)\left(x-1\right)}{\left(2x^2+x-3\right)\left(x-1\right)}\)
\(=\frac{3x^2-4x+1}{2x^2+x-3}\)
\(=\frac{3x^2-3x-x+1}{2x^2-2x+3x-3}\)
\(=\frac{\left(3x^2-3x\right)-\left(x-1\right)}{\left(2x^2-2x\right)-\left(3x-3\right)}\)
\(=\frac{3x\left(x-1\right)-\left(x-1\right)}{2x\left(x-1\right)-3\left(x-1\right)}\)
\(=\frac{3x-1}{2x-3}\)
Đúng 0
Bình luận (0)
Rút gọn rồi tính A vs x =2
A=(7x−8).(7x+8)−10.(2x+3)^2+5x.(3x−2)^2−4x.(x−5)^2
Rút gọn :
1. (2x-5)(3x+1)-(x-3)^2+(2x+5)^2-(3x+1)^3
2. (2x-1)(2x+1)-3x-2)(2x+3)-(x-1)^3+(2x+3)^3
3. (x-2)(x^2+2x+4)-(3x-2)^3+(3x-4)^2
4. (7x-1)(8x+2)-(2x-7)^2-(x-4)^3-(3x+1)^3
5. (5x-1)(5x+1)-(x+3)(x^2-3x+9)-(2x+4)^2-(3x-4)^2+(2x-5)^3
6. (4x-1)(x+2)-(2x+5)^2-(3x-7)^2+(2x+3)^3=(3x-1)^3
1: \(=6x^2+2x-15x-5-x^2+6x-9+4x^2+20x+25-27x^3-27x^2-9x-1\)
=-27x^3-18x^2+4x+10
2: =4x^2-1-6x^2-9x+4x+6-x^3+3x^2-3x+1+8x^3+36x^2+54x+27
=7x^3+37x^2+46x+33
5:
\(=25x^2-1-x^3-27-4x^2-16x-16-9x^2+24x-16+\left(2x-5\right)^3\)
\(=8x^3-60x^2+150-125+12x^2-x^3+8x-60\)
=7x^3-48x^2+8x-35
Đúng 0
Bình luận (0)
rút gọn các biểu thức sau:
a)5x^2(3x^2-7x+2)-15x(x-3)
b)2/3xy(2x^2y-3xy+y^2)-2/3xy^3
c) (x+3)(x-3)-(x-2)(x+1)
d) (2x+1)^2+(4x-1)^2+2(2x+1)(4x-1)
e) (2x^2-3x)(5x^2-2x+1)-10x(x+3)
a) 5x2 ( 3x2 -7x+2)-15x(x-3)
=15x4-35x3+10x2-15x2+45x
=15x4-35x3-5x2+45x
c) (x+3)(x-3)(x-2)(x+1)
=(x2-9)(x2+x-2x-2)
=(x2-9)(x2-x-2)
=x4-x3-2x2-9x2+9x+18
=x4-x3-11x2+9x+18
d)(2x+1)2+(4x-1)2+2(2x+1)(4x+1)
=2x2+4x+1-16x2-8x+1
=2x2+4x+1-16x2-8x+1+16x2-4x+8x-2
=2x2+7
e) (2x2-3x)(5x2-2x+1)-10x2(x+3)
=10x4 -4x3+2x2-15x3+6x2-3 -10x2-30x
=10x4-19x3-2x2-30x-3
Đúng 0
Bình luận (0)
Xem thêm câu trả lời
Rút gọn ( 3x3 - 7x2 + 5x - 1)/( 2x3 - x2 - 4x +3)
\(\frac{3x^3-7x^2+5x+1}{2x^3-x^2-4x+3}\)
= \(\frac{\left(3x^2-4x+1\right)\left(x-1\right)}{\left(2x^2+x-3\right)\left(x-1\right)}\)
= \(\frac{\left(3x^2-x-3x+1\right)\left(x-1\right)}{\left(2x^2+3x-2x-3\right)\left(x-1\right)}\)
= \(\frac{\left[x\left(3x-1\right)-\left(3x-1\right)\right]\left(x-1\right)}{\left[x\left(2x+3\right)-\left(2x+3\right)\right]\left(x-1\right)}\)
= \(\frac{\left(3x-1\right)\left(x-1\right)\left(x-1\right)}{\left(2x+3\right)\left(x-1\right)\left(x-1\right)}\)
= \(\frac{\left(3x-1\right)\left(x-1\right)^2}{\left(2x+3\right)\left(x-1\right)^2}\)
= \(\frac{3x-1}{2x+3}\)
Rút gọn 3x3 - 7x2 + 5x - 1 / 2x3 - x2 - 4x + 3
rút gọn phân thức \(\frac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}\)
Rút gọn:
a , (7x-8)(7x+8)-10(2x+3)2+5x(3x-2)2-4x(x-5)2
b , (x2-3)(x2+3)-5x2(x+1)2-(x2-3x)(x2-2x)+4x(x+2)2
Giúp mình với:))
a) (7x - 8)(7x + 8) - 10(2x + 3)2 + 5x(3x - 2)2 - 4x(x - 5)2
= 49x2 - 64 - 10(4x2 + 12x + 9) + 5x(9x2 - 12x + 4) - 4x(x2 - 10x + 25)
= 49x2 - 64 - 40x2 - 120x - 90 + 45x3 - 60x2 + 20x - 4x3 + 40x - 100x
= 41x3 - 51x2 - 160x - 154
b) (x2 - 3)(x2 + 3) - 5x2(x + 1)2 - (x2 - 3x)(x2 - 2x) + 4x(x + 2)2
= x4 - 9 - 5x2(x2 + 2x + 1) - x4 + 5x3 - 6x2 + 4x(x2 + 4x + 4)
= 5x3 - 6x2 - 5x4 - 10x3 - 5x2 + 4x3 + 16x2 + 16x - 9
= -5x4 - x3 + 5x2 + 16x - 9
Trả lời:
a , ( 7x - 8 ) ( 7x + 8 ) - 10 ( 2x + 3 )2 + 5x ( 3x - 2 )2 - 4x ( x - 5 )2
= 49x2 - 64 - 10 ( 4x2 + 12x + 9 ) + 5x ( 9x2 - 12x + 4 ) - 4x ( x2 - 10x + 25 )
= 49x2 - 64 - 40x2 + 120x - 90 + 45x3 - 60x2 + 20x - 4x3 + 40x2 - 100x
= 41x3 - 11x2 + 40x - 154
b , ( x2 - 3 ) ( x2 + 3 ) - 5x2 ( x + 1 )2 - ( x2 - 3x ) ( x2 - 2x ) + 4x ( x + 2 )2
= x4 - 9 - 5x2 ( x2 + 2x + 1 ) - ( x4 - 2x3 - 3x3 + 6x2 ) + 4x ( x2 + 4x + 4 )
= x4 - 9 - 5x4 - 10x3 - 5x2 - x4 + 2x3 + 3x3 - 6x2 + 4x3 + 16x2 + 16x
= - 5x4 - x3 + 5x2 + 16x - 9