Rút gọn biểu thức
a) (2 $x^{2}$ + 1).( $x^{2}$ -2x -1)
b) ( x-2).(3-2x) .(2x+3)
c) ( x-2y)^2 -3( x+y)^2
d) -2.(x-1)^2 -3.(2-x)^2
Rút gọn biểu thức a) (2 $x^{2}$ + 1).( $x^{2}$ -2x -1) b) ( x-2).(3-2x) .(2x+3) c) ( x-2y)^2 -3( x+y)^2 d) -2.(x-1)^2 -3.(2-x)^2
By Iris
`a,(2x² + 1).(x² -2x -1)`
`= 2x^4-4x³-x²-2x-1`
`b,( x-2).(3-2x) .(2x+3)`
`= -4x³+8x²+9x-18`
`c,( x-2y)^2 -3( x+y)^2`
`= -2x²+y²-10xy`
`d,-2.(x-1)^2 -3.(2-x)^2`
`= -5x²+16x-14`
Xin hay nhất !