Unlike terms displays terms which are not the same. x+2y would be the answer.
If you add the standard deviation to the average, it is 14.84. Because Marcus's score was lower than that, he will not receive a certificate.
I think this should be right for the reason and the calculation.
The probability that the first horse wins is 2/7. The probability that the second horse wins is 3/10. Since the events that the first horse wins and the second horse wins are shared exclusive, the probability that either the first horse or the second horse will win is :
2/7 + 3/10= 41/70
Hope this is correct.
