The answer is C
4(3-x)+6x=3x+12-x All real numbers are solutions.
Step-by-step explanation:
To multiply the fractions, like

Multiply the top,
then multiply the bottom.

Try to use a calculator if you aren't arithmetic heavy, but I suggest you to try to remember them because they are going to be helpful for courses like Algebra, Calculus, Statistics, etc.
To divide fractions, like

You take the top number,

Then you flip the bottom number,

Then multiply the two

And that is your answer. Comment if you need more clarification
Answer: Option 'D' is correct.
Step-by-step explanation:
Since we have given that
Upper P (Upper B vertical line Upper A)
means

It means that probability of getting event B given that Event A is occurred.
D. The probability of event B occurring, given that event A has already occurred. is also expressed as 
Hence, Option 'D' is correct.