Answer:
0.15866 is the probability of the average fracture strength of selected 100 pieces of glasses that of exceed 14.3.
Step-by-step explanation:
Given that, the strength of a tempered(x) a glass has average 14.1 and has standard deviation 2.
, 
n=number of selected pieces= 100.
The probability that the average fracture strength of 100 pieces of this glass exceed 14.3 is



= 1 - 0.84134
=0.15866.
Answer 17/18 , 19,20
Step-by-step explanation:
Combine like terms
2m and -4m are like terms while 3m^2 isnt. So, leave 3m^2 as it is and combine the other set. 2m-4m = (-2m). Therefore, your answer should be 3m^2 - 2m