2⁴ x 5⁵ = 2⁴ x 5⁴ x 5 = ( 2 x 5 )⁴ x 5 = 5 x 10⁴ = 5 x 10 000 = 50 000
2⁴·5⁵ = 16·625·5 = 10000·5 = 50000