thực hiện phép tính
a)(5x-3)(5x+3); b) (2x^2)-3x(4x^2-5x+6); c) 16x^3y^4:4x^2y^2
Câu 2 thực hiện phép tính
a. x + 2² - x - 3 (x + 1)
b. x³ - 2x² + 5x - 10 : ( x - 2)
Bài 2
A = (x + 2)^ 2 - x - 3 x (x + 1) = x² + 4x + 4 - x² + 2x + 3 = 6x + 7
B = x^3 - 2x² + 5x - 10 = x² x (x - 2) + 5 x (x - 2) = (x - 2) x (x² + 5)
Vậy x^3 - 2x² + 5x - 10 : (x - 2) = x² + 5
Bài 1: Thực hiện phép tính
a)5x3(3x2 – 5x + 3) c)x2 ( 2x3 – 4x + 3)
b) -1\(\dfrac{1}{2}\)x22x – 1)(x2 + 5x – 4) d) (3x – 4)(2x + 4) + (5 – x)(2x2 + 3x – 2)
a: \(=15x^5-25x^4+15x^3\)
b: \(=2x^3+10x^2-8x-x^2-5x+4\)
\(=2x^3+9x^2-13x+4\)
thực hiện phép tính
a.\(\dfrac{x}{3x+y}+\dfrac{x}{3x-y}-\dfrac{2xy}{y^2-9x^2}\)
b.\(\dfrac{4x+5}{x^2+5x}-\dfrac{3}{x+5}\)
ĐKXĐ: \(\left\{{}\begin{matrix}3x\ne-y\\3x\ne y\end{matrix}\right.\)
a. \(\dfrac{x}{3x+y}+\dfrac{x}{3x-y}-\dfrac{2xy}{y^2-9x^2}\)
\(=\dfrac{x.\left(3x-y\right)}{\left(3x+y\right).\left(3x-y\right)}+\dfrac{x.\left(3x+y\right)}{\left(3x+y\right).\left(3x-y\right)}+\dfrac{2xy}{9x^2-y^2}\)
\(=\dfrac{x.\left(3x+y+3x-y\right)+2xy}{\left(3x-y\right).\left(3x+y\right)}\)
\(=\dfrac{6x^2+2xy}{\left(3x-y\right).\left(3x+y\right)}\)
\(=\dfrac{2x\left(3x+y\right)}{\left(3x+y\right).\left(3x-y\right)}\)
\(=\dfrac{2x}{3x-y}\)
ĐKXĐ: \(\left\{{}\begin{matrix}x\ne0\\x\ne-5\end{matrix}\right.\)
b. \(\dfrac{4x+5}{x^2+5x}-\dfrac{3}{x+5}\)
\(=\dfrac{4x+5}{x.\left(x+5\right)}-\dfrac{3x}{x.\left(x+5\right)}\)
\(=\dfrac{x+5}{x.\left(x+5\right)}\)
\(=\dfrac{1}{x}\)
a) Ta có: \(\dfrac{x}{3x+y}+\dfrac{x}{3x-y}-\dfrac{2xy}{y^2-9x^2}\)
\(=\dfrac{x\left(3x-y\right)}{\left(3x+y\right)\left(3x-y\right)}+\dfrac{x\left(3x+y\right)}{\left(3x+y\right)\left(3x-y\right)}+\dfrac{2xy}{\left(3x+y\right)\left(3x-y\right)}\)
\(=\dfrac{3x^2-xy+3x^2+xy+2xy}{\left(3x+y\right)\left(3x-y\right)}\)
\(=\dfrac{6x^2+2xy}{\left(3x+y\right)\left(3x-y\right)}\)
\(=\dfrac{2x\left(3x+y\right)}{\left(3x+y\right)\left(3x-y\right)}\)
\(=\dfrac{2x}{3x-y}\)
b) Ta có: \(\dfrac{4x+5}{x^2+5x}-\dfrac{3}{x+5}\)
\(=\dfrac{4x+5}{x\left(x+5\right)}-\dfrac{3x}{x\left(x+5\right)}\)
\(=\dfrac{4x+5-3x}{x\left(x+5\right)}\)
\(=\dfrac{x+5}{x\left(x+5\right)}\)
\(=\dfrac{1}{x}\)
Bài 1 làm tính nhân
2x.(x^2-7x-3)
(-2x^3+y^2-7xy).4xy^2
(-5x^3).(2x^2+3x-5)
(2x^2-xy+y^2).(-3x^3)
(x^2-2x+3).(x-4)
(2x^3-3x-1).(5x+2)
Bài 2 Thực hiện phép tính
A,(2x+3y^2)
B, (5x-y)^2
C, (2x+y^2)^3
D, ( 3x^2-2y)^3
\(2x\left(x^2-7x-3\right)=2x^3-14x-6x\)
\(4xy^2\left(-2x^3+y^2-7xy\right)=-8x^4y^2+4xy^5-28x^2y^3\)
Bài 1 : Thực hiện phép tính
a) 3x (x^2 - 7x + 9)
b) (x+3y) (x^2 - 2xy + y)
c) (5x - 2y) (x^2 - xy + 1)
Bài 2 : Tìm x , biết
a) x (5x - 2y) + 2x ( x - 1) = 15
b) x^2 - 25x = 0
c) 5x (x - 1) = x - 1
Bài 3 : Phân tích đa thức thành nhân tử
a) x^2 .16
b) x^2 + 2x - y^2 + 1
c) x^2 - 2xy - 4 + y^2
Bài 3:
a: \(x^2-16=\left(x-4\right)\cdot\left(x+4\right)\)
b: \(x^2+2x+1-y^2=\left(x+1+y\right)\left(x+1-y\right)\)
c: \(=\left(x-y\right)^2-4=\left(x-y-2\right)\left(x-y+2\right)\)
a, Thực hiện phép nhân 4x\(^2\) ( x\(^2\) - 5x + 2 )
b, Thực hiện phép chia ( 2x\(^2\) - 5x + 3 ) : ( 2x - 3 )
a) 4x²(x² - 5x + 2)
= 4x².x² - 4x².5x + 4x².2
= 4x⁴ - 20x³ + 8x²
b) (2x² - 5x + 3) : (2x - 3)
= (2x² - 3x - 2x + 3) : (2x - 3)
= [(2x² - 3x) - (2x - 3)] : (2x - 3)
= [x(2x - 3) - (2x - 3)] : (2x - 3)
= (2x - 3)(x - 1) : (2x - 3)
= x - 1
a, \(4x^2\left(x^2-5x+2\right)\\ =4x^4-20x^3+8x^2\)
b, \(\left(2x^2-5x+3\right):\left(2x-3\right)\\ =x-1\)
Bài 1:Thực hiện phép tính
a,(5-2x)(x+3)-4x(x+2) b,(3x+1)(x-3)-4(x+2)(x-2)
c,3(x-4)(x+3)+(x-5)(x+3) d,2x(x-4)+(3x-1)(2x-5)
Bài 2:Tìm x biết
a,5x(x+3)-(5x+2)(x+3)=7
b,(3x-1)(3x+2)-9(x+2)(x-2)=10
c,(x+1)(2x-5)+2(3-x)(x+2)=7
d,(1-3x)(x+2)+3x(x-5)=8
bài 5: thực hiện phép tính
a) ( x + 3y ) ( x - 2y )
b) ( 2x - y ) ( y - 5x )
c) ( 2x - 5y ) ( y^2 - 2xy )
d) ( x - y ) ( x^2 - xy - y^2 )
\(a)\left(x+3y\right)\left(x-2y\right)\\ =x^3-2xy+3xy-6y^2\\ =x^2+xy-6y^2\\ b)\left(2x-y\right)\left(y-5x\right)\\ = 2xy-10x^2-y^2+5xy\\ =7xy-10x^2-y^2\\ c)\left(2x-5y\right)\left(y^2-2xy\right)\\ =2xy^2-4x^2y-5y^3+10xy^2\\ =12xy^2-4x^2y-5y^2\\ d)\left(x-y\right)\left(x^2-xy-y^2\right)\\ =x^3-x^2y-xy^2-x^2y+xy^2+y^3\\ =x^3-2x^2y+y^3\)
thực hiện phép tính
a) 5x(3x2-4x+2)
b)(x2-3x)(3x2-x+4)
2) tìm x biết
a) x3-6x2+12x=0
b)x3+9x2+27x+27=0
giúp mình mn ơi
thực hiện phép tính
a) 5x(3x2-4x+2)
b)(x2-3x)(3x2-x+4)
2) tìm x biết
a) x3-6x2+12x=0
b)x3+9x2+27x+27=0
giúp mình mn ơi
1)
a) \(=15x^3-20x^2+10x\)
b) \(=3x^4-x^3+4x^2-9x^3+3x-12x=3x^4-10x^3+4x^2-9x\)
2)
a) \(\Rightarrow x\left(x^2-6x+12\right)=0\)
\(\Rightarrow x=0\)(do \(x^2-6x+12=\left(x^2-6x+\dfrac{36}{4}\right)+3=\left(x-\dfrac{6}{2}\right)^2+3\ge3>0\))
b) \(\Rightarrow\left(x+3\right)^3=0\Rightarrow x=-3\)
(3x²-5x+2)+(3x²+5x)= bao nhiêu ạ
Giúp em vs ạ . Em cảm ơn