This is the fundamental zero additive rule
x - 0 = x
which means that for the set of real numbers, there exist a number such that if added (or subtracted) from any other will not affect such number.
Answer:
Sum of 3 angles in a triangle=180
x+55+72= 180
x+ 127=180
x= 180-127
x= 53
32yd is longer as 32yd is equivalent to 96ft
Answer: -2.10
Step-by-step explanation:
Given : 

Sample size : n= 50, since the sample size is greater than 30 , so we apply z-test.
Sample mean : 
Standard deviation : 
The test statistic for population mean :-

i.e. 
Hence, the value of the test statistic = -2.10
75% of the whole length is 30 cm
(30x100)/75=40cm
So a=40 cm