Multiply:

(3 x 10^8) (1.3 x 10^3)

3.9 X 10^11

Step-by-step explanation:

(3 x 10^8) (1.3 x 10^3)

Step 1: The bases with exponents are the same so put those together!

(3 x 1.3) (10^8 x 10^3)

Step 2: Since both bases are together ADD them, the rest you can continue as is

(3 x 1.3) (10^8+3)

Step 3: Solve!

3.9 x 10^11