Answer:
Step-by-step explanation:
a)
9*10⁷ = 90000*10³
(5*10³)*(9*10⁷) = (5*10³)*(90000*10³) = (5*90000)*10³ = 5*90000*10000
= 4500000000
b)
(7*10⁵) = (7000*10²)
(7*10⁵) ÷ (2*10²) = (7000*10²) ÷ (2*10²) = (7000 ÷ 2) * 10² = 3500*10²
=350000
