Answer:
Step-by-step explanation:
By the definition of an angle bisector, we have that 
.
We can add 
to both sides to get 
.
We can then subtract 
from both sides to get 
.
We can finally divide both sides by 
to get 
The sample which is likely to produce the most valid result is Richard's sample because there was no statistical bias. Statistical bias is the systematic favoritism of certain individuals in the study. Just like what Adriana, Henry and Malik did in conducting their surveys, they choose people who are point of interest and also who are near them. In the way Richard conducted his survey, he used a random sampling technique, this is a method of selecting a sample from a population in such a way that every possible individual can be chosen and he doesn't know who these people are.
Answer:
7x^2+9x
Step-by-step explanation:
Hope this helps...
7x^2+(5x+4x)=
7x^2=9x
