利用因式分解计算：1、1.22^×9-1.33^2×4 2、2.83×77

1.22^×9-1.33^2×4
=(1.22x3)²-(1.33x2)²
=3.66²-2.66²
=(3.66+2.66)(3.66-2.66)
=6.32x1
=6.32
83×77
=(80+3)(80-3)
=80²-3²
=6400-9
=6391