Answer:
-27/7
Step-by-step explanation:
put x into the equation
Answer:


Step-by-step explanation:










Answer:
The estimate is 
Step-by-step explanation:
From the question we are told that
The sample size is n = 522
The sample proportion of students would like to talk about school is 
Given that the confidence level is 90 % then the level of significance can be mathematically evaluated as



Next we obtain the critical value of
from the normal distribution table, the value is

Generally the margin of error can be mathematically represented as

=> 
=> 
Generally the estimate the proportion of all teenagers who want more family discussions about school at 90% confidence level is

substituting values

I don't get your question but
> x + y
No. Just because the angles are all less than 90 degrees, that doesn't tell us anything about the sides. The sides are all congruent ONLY if all 3 angles are 60 degrees each. If the angles all have different sizes, then so do the sides.