i need some help with 7-8-9
7. Perform the operation and write your answer in scientific notation.
2.4 x 10^-9
——————
8x10^6
8. Perform the operation and write your answer in scientific notation.
(5x10^8) - (3.4x10^8)
9. Perform the operation and write your answer in scientific notation.
(3 x 10-8) + (2x× 10-6)