Cần gấp trước 9h
a ) x ² – 2xy +5x – 10y
b ) x ( 2x – 3y ) – 6y ² + 4xy
c ) m ² – m – n ² – n`
Cần gấp trước 9h a ) x ² – 2xy +5x – 10y b ) x ( 2x – 3y ) – 6y ² + 4xy c ) m ² – m – n ² – n`
By Quinn
By Quinn
Cần gấp trước 9h
a ) x ² – 2xy +5x – 10y
b ) x ( 2x – 3y ) – 6y ² + 4xy
c ) m ² – m – n ² – n`
$#DYHUN$
`a) x²-2xy+5x-10y`
`=x(x-2y)+5(x-2y)`
`=(x-2y)(x+5)`
`b)x(2x-3y)-6y²+4xy`
`=2x²-3xy-6y²+4xy`
`=(2x²+4xy)-(3xy+6y²)`
`=2x(x+2y)-3y(x+2y)`
`=(x+2y)(2x-3y)`
`c)m²-m-n²-n`
`=(m²-n²)-(m+n)`
`=(m-n)(m+n)-(m+n)`
`=(m+n)(m-n-1)`
Đáp án:
Giải thích các bước giải:
a)a ) x ² – 2xy +5x – 10y
⇔ (x²-2xy)+(5x-10y)
⇔ x(x-2y)+5( x-2y)
⇔ (x+5)(x-2y)
b ) x ( 2x – 3y ) – 6y ² + 4xy
⇔ x ( 2x – 3y )-2(3y-2x)
(2x-3y)(x-2)
c ) m ²- m – n ² – n`
⇔(m²-n²)-(m-n)
⇔(m-n)(m+n)-(m-n)
⇔(m-n)(m+n-1).