a)0,5 x2y( 2x3 - 0,4 xy2 - 1)
b) (x2 - 1 )(x2 + 2x - 1)
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a) \(3x\left(5x^2-2x-1\right)\)
\(=3x.5x^2-3x.2x+3x.\left(-1\right)\)
\(=15x^3-6x^2-3x\)
b) \(\left(x^3-2xy+3\right)\left(-xy\right)\)
\(=\left(-xy\right).\left(x^2+2xy-3\right)\)
\(=\left(-xy\right).x^2+\left(-xy\right).2xy+\left(-xy\right).\left(-3\right)\)
\(=x^3y-2x^2y^2+3xy\)
mấy câu sau vt lại đè
c)x2y(2x3 - xy2 - 1);
d)x(1,4x - 3,5y);
e)xy(x2 - xy + y2);
f)(1 + 2x - x2)5x;
g) (x2y - xy + xy2 + y3). 3xy2;
h) x2y(15x - 0,9y + 6);
Đây ạ giúp mik vs bt tết đs mng :<
a: \(\dfrac{1}{2}x^2y\left(2x^3-\dfrac{2}{5}xy^2-1\right)\)
\(=x^5y-\dfrac{1}{5}x^3y^3-x^2y\)
b: \(\left(\dfrac{1}{2}x-5\right)\left(x^2-2x+3\right)\)
\(=\dfrac{1}{2}x^3-x^2+\dfrac{3}{2}x-5x^2+10x-15\)
\(=\dfrac{1}{3}x^3-6x^2+\dfrac{23}{2}x-15\)
Làm tính nhân:
a. 3 x(5x2 - 2x -1) = 15x3 - 6x2 - 3x
b. (x2+2xy -3)(-xy) = - x3y – 2x2y2 + 3xy
c. 1/2 x2y ( 2x3 - 2/5 xy2 -1 )= x5y - 1/5 x3y3 - 1/2 x2y
\(a,=5\left(x-y\right)+a\left(x-y\right)=\left(5+a\right)\left(x-y\right)\\ b,=a\left(x+y\right)+b\left(x+y\right)=\left(a+b\right)\left(x+y\right)\\ c,=x\left(x+1\right)+a\left(x+1\right)=\left(x+a\right)\left(x+1\right)\\ d,Sửa:x^2y+xy^2-3x-3y=xy\left(x+y\right)-3\left(x+y\right)=\left(xy-3\right)\left(x+y\right)\\ e,=xy\left(x+1\right)-\left(x+1\right)=\left(xy-1\right)\left(x+1\right)\\ f,=x^2-4=\left(x-2\right)\left(x+2\right)\\ g,=\left(x+3\right)^2-y^2=\left(x-y+3\right)\left(x+y+3\right)\\ h,=\left(x+5\right)^2-y^2=\left(x-y+5\right)\left(x+y+5\right)\\ i,=\left(x-4\right)^2-24y^2=\left(x-2\sqrt{6}y-4\right)\left(x+2\sqrt{6}y+4\right)\)
\(A=5x^2y-xy^2+4xy+6\) bậc : 3
a)\(B=-5x^2y+xy^2-4xy-6\)
b)\(=>C=-2xy+1-5x^2y+xy^2-4xy-6\)
\(C=-5x^2y+xy^2-6xy-5\)
a: \(\dfrac{\left(x+1\right)}{x^2+2x-3}=\dfrac{\left(x+1\right)}{\left(x+3\right)\cdot\left(x-1\right)}=\dfrac{\left(x+1\right)\left(x+2\right)\left(x+5\right)}{\left(x+3\right)\left(x-1\right)\left(x+2\right)\left(x+5\right)}\)
\(\dfrac{-2x}{x^2+7x+10}=\dfrac{-2x}{\left(x+2\right)\left(x+5\right)}=\dfrac{-2x\left(x+3\right)\left(x-1\right)}{\left(x+2\right)\left(x+5\right)\left(x+3\right)\left(x-1\right)}\)
b: \(\dfrac{x-y}{x^2+xy}=\dfrac{x-y}{x\left(x+y\right)}=\dfrac{y^2\left(x-y\right)}{xy^2\left(x+y\right)}\)
\(\dfrac{2x-3y}{xy^2}=\dfrac{\left(2x-3y\right)\left(x+y\right)}{xy^2\left(x+y\right)}\)
c: \(\dfrac{x-2y}{2}=\dfrac{\left(x-2y\right)\left(x-xy\right)}{2\left(x-xy\right)}\)
\(\dfrac{x^2+y^2}{2x-2xy}=\dfrac{x^2+y^2}{2\left(x-xy\right)}\)
Sửa đề: \(A=x^3+x^2y-xy^2-y^3+x^2-y^2+2x+2y+3\)
\(A=x^2\left(x+y\right)-y^2\left(x+y\right)+\left(x-y\right)\left(x+y\right)+2x+2y+3\)
\(=-x^2+y^2+\left(-x+y\right)-2+3\)
\(=-\left(x-y\right)\left(x+y\right)-\left(x-y\right)+1\)
\(=\left(x-y\right)\left(-x-y-1\right)+1\)
\(=\left(x-y\right)\left(1-1\right)+1=1\)
Đề là gì vậy??? Nếu là thực hiện phép tính thì tớ làm nhé !
a) 0,5x2y( 2x3 - 0,4xy2 - 1)
= x5y - 0,2x3y3 - 0,5x2y
b) ( x2 - 1)( x2 + 2x - 1)
= x4 + 2x3 - x2 - x2 - 2x + 1
= x4 + 2x3 - 2x2 - 2x + 1
= ( x2 - 1)2 + 2x( x2 - 1)
= ( x2 - 1)( x2 + 2x + 1- 1)
= ( x2 - 1)( x2 + 2x)