(-2x+3y)平方=(2x-3y)²=4x²-12xy+9y²
.
2.(x-2y+3)(x+2y+3)
=[(x+3)-2y][(x+3)+2y]
=(x+3)²- 4y²
=x²+6x+9-4y²
.
3.(2分之1)的-1次方+(π-2012)的0次方-(-3分之2)的-2次方
=2 + 1 - (-2分之3)²
=3 - (4分之9)
=4分之3
(-2x+3y)平方=(2x-3y)²=4x²-12xy+9y²
.
2.(x-2y+3)(x+2y+3)
=[(x+3)-2y][(x+3)+2y]
=(x+3)²- 4y²
=x²+6x+9-4y²
.
3.(2分之1)的-1次方+(π-2012)的0次方-(-3分之2)的-2次方
=2 + 1 - (-2分之3)²
=3 - (4分之9)
=4分之3