Step-by-step explanation:
51 is not a prime number because it is divisible by 1,3 and 17
and we know prime number are only those number who arenot divisible by any other number except 1
Answer: 
<u>Add 3x to both sides</u>
<u></u>
<u></u>
<u></u>
<u>Subtract 15 from both sides</u>
<u></u>
<u></u>
<u></u>
<u>Divide both sides by 5</u>
<u></u>
<u></u>
1.567038973 is the answer
The answer is either c or b because i think they are the same