mbi53 mbi53 19-01-2021 Mathematics contestada For each calculation choose the correct answer written in standard form. a) (7 * 10%) * (3 x 10) А B 21 x 100 21 x 10 с 2.1 x 10" D 2.1 x 10 b) (2 * 10%) = (4 * 10) А 2* 10 B 5 x 10 C 0.5 x 10 D 2 x 10