Question

Tính:

a) 5x²y - xy

b) 3x( x - 2 ) + 5(2 - x)

c) x²+2x +1 + 9y²

d) x² - 5y - xy + 5x

giúp mình vs ;-;

Answer 1

\(a,=xy\left(5x-1\right)\\ b,=\left(x-2\right)\left(3x-5\right)\\ c,Sửa:x^2+2x+1-9y^2\\ =\left(x+1\right)^2-9y^2\\ =\left(x-3y+1\right)\left(x+3y+1\right)\\ d,=x\left(x-y\right)+5\left(x-y\right)=\left(x+5\right)\left(x-y\right)\)

Answer 2

â) \(=xy\left(5x-1\right)\)

b) \(=\left(3x-5\right)\left(x-2\right)\)

c) \(=\left(x+1\right)^2+\left(3y\right)^2=\left(x+1\right)^2+6y\left(x+1\right)+\left(3y\right)^2-6y\left(x+1\right)=\left(x+1+3y\right)^2-\sqrt{\left[6y\left(x+1\right)\right]^2}=\left(x+3y+1-\sqrt{6y\left(x+1\right)}\right)\left(x+3y+1+\sqrt{6y\left(x+1\right)}\right)\)

d) \(=\left(x^2+5x\right)-\left(5y+xy\right)=x\left(x+5\right)-y\left(5+x\right)=\left(x-y\right)\left(x+5\right)\)