Answer:
A
Step-by-step explanation:
Answer: Choice D. 
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Work Shown:
We multiply the coefficients 9.2 and 7 to get 64.4, which is the same as 6.44*10^1 in scientific notation. When multiplying exponential expressions with the same base, we add the exponents
This is what the steps could look like

The final result is in scientific notation as the coefficient c is restricted such that 
19b-(-10b)-(-2b)-(-3b)-20b = 14
14b=14 Simplify
b=1 Divide
You are posting a lot of these types of problems. Maybe the course you are taking is to difficult for you?
Answer:
14
Step-by-step explanation:
its not 14 but there is no answer to it because there are multipul equel signs