câu 1 phân tích đa thức thành nhân tử
a ) x mũ 3 + 2 x b ) 0 3 x mũ 2 y – 6xy + 12xy mũ 2 z
c ) 3x mũ 3 – 12 x mũ 2 d ) 3 ( x – y ) – 5y (y – x )
e ) 5 ( x + 3y ) – 15 x ( x + 3y ) f ) 2x ( x-y ) – 4y mũ 2 + 4 x mũ 2
giúp mik nha cần gấp
Đáp án:
Giải thích các bước giải:
Câu 1 :
a) x³ + 2x = x(x² + 2)
b) 3x²y – 6xy + 12xy²z
= 3xy(x – 2 + 4yz)
c) 3x³ – 12x²
= 3x²(x – 4)
d) 3(x – y) – 5y(y – x)
= 3(x – y) + 5y(x – y)
= (x – y)( 3 + 5y)
e) 5( x + 3y) – 15x(x + 3y)
= ( x + 3y)(5 – 15x)
= 5(x + 3y)(1 – 3x)
f) 2x(x – y) – 4y² + 4x²
= 2x( x – y) – 4( y² – x²)
= 2x(x – y) + 4(x – y)( x + y)
= (x – y)[ 2x + 4(x + y)]
= ( x – y)( 2x + 4x + 4y)
= ( x – y)( 6x + 4y)
= 2( x – y)( 3x + 2y)
`a)3x^2+2x=x(3x+2)`
`b ) 3 x ^ 2 y – 6xy + 12xy ^ 2 z`
`=xy (3 x – 6 + 12y z)`
`d ) 3 ( x – y ) – 5y (y – x ) `
`= 3 ( x – y ) + 5y (x – y ) `
`= ( x – y ) (3+ 5y ) `
`e ) 5 ( x + 3y ) – 15 x ( x + 3y ) `
` =( x + 3y )(5 – 15 x)`
`f ) 2x ( x-y ) – 4y ^2 + 4 x^2`
`= 2x ( x-y ) – 4(y ^2 – x^2)`
`= 2x ( x-y ) – 4(y – x)(y+x)`
`= 2x ( x-y ) + 4(x – y)(y+x)`
`= ( x-y ) [2x+4(y+x)]`
`= 2( x-y ) [x+2(y+x)]`
`= 2( x-y ) (3x+2y)`