4x 2x 1 8 0 July 8, 2019 16 32 64 128 4x 1 0.5 3 2x =( 1 8 x 4x 8 2x 2 1 0 2x 4x 8 )( x 1 )= 0 4x 8 4 2x x 2 1 0 4x 乗 2x 1 乗 8 0