gimana sih ini?dengan cara nya?bingung ni?bantuin dong

1)
7 x 207 = 7 x (200 +7)
             = (7 x 200) + (7 x 7)
             = 1.400 + 49
             = 1.449

2)
4 x 21 x 72 = 4 x 72 x 21
                   = 4 x 1.512
                   = 6.048

3)
22 + 28 = 28 + 22 = 50

1.) 207 × 7 = 1449
2.) 4 × 21 × 72 = 6048
3.) 22+28= 50