a) 5.(x-y)-y(x-y)
= (x-y)(5-y)
b) y.(x-2)+7(2-x)
= y.(x-2) -7(x-2)
=(x-2)(y-7)
c) sửa lại đề
272.(y-1) -9x3(1-y)
=272.(y-1) + 9x3(y-1)
= (y-1)(272+9x3)
d) 4x(x-2016-x+2016)
= 4x.0
= 0
e) (2x-1)3 - 2x+1
= (2x-1)3 - (2x-1)
= (2x-1)[(2x-1)2-1]
=(2x-1)(2x-1-1)(2x-1+1)
=2x.(2x-1)(2x-2)
=4x.(x-1)(2-1)
m) 25-(3-x)2
= [5-(3-x)][5+(3-x)]
=(5-3+x)(5+3-x)
n) (x-5)2=16
=> (x-5)2=42 hoặc (x-5)2=(-4)2
=> (x-5)=4 hoặc x-5=-4
trường hợp 1
x-5=4
x= 4+5
x=9
trường hợp 2
x-5=-4
x=-4+5
x=1
vậy x=9 hoặc x=1
a) \(5.\left(x-y\right)-y.\left(x-y\right)=\left(x-y\right)\left(5-y\right)\)
b) \(y.\left(x-2\right)+7.\left(2-x\right)=\left(x-2\right)\left(y+7\right)\)
