4. Express the answers to the following problems in scientific notation. Hint: Use the subtraction example to solve the addition problem. A. (1.8 X 1020) X (2.5 X 10^16) C. (9.2 X 10^19) ÷ (3.0 X 10^7) B.(7.9 X 10^9) - (6.0 X 10^8) D. (4.2 X 10^9) + (8.0 X 10^18)

see below

Explanation:

A. (1.8 X 10^20) X (2.5 X 10^16)

= 4.5 x 10³⁶

B.(7.9 X 10^9) - (6.0 X 10^8)

= 7.3 x 10⁹

C. (9.2 X 10^19) ÷ (3.0 X 10^7)

= 3.067 x 10¹²

D. (4.2 X 10^9) + (8.0 X 10^18)

= 8.00000002042 x 10¹⁸

r just means there's a number of carbon in teh chain. for example rcooh means that after x number of carbon, the chain ends with cooh.

explanation:

the answer is a and have a great day