Which equation is true?

(3.4 x 104) ÷ (1.5 X 106) = 5.1 x 102

(5.8 x 105)(2 x 103) = 2.9 x 108

(3.6 x 107) ÷ (1.2 x 102) = 3 x 105

(2.4 x 105)(3 x 103) = 7.2 x 102