Answer:
B. Number the students on the school roster. Use a table of random numbers to choose 160 students from this roster for the survey.
Step-by-step explanation:
I am unsure about the very last problem but I can help with the first two
1) (y+1)+4
If we combine the numbers 1 and 4, we get +5 and can isolate the numbers from the variable.
This would give us

2) (6*r)*7
remember that we do not have to explicitly state 6*r
Instead, we can write it as 6r
this helps us get rid of the parentheses
now we can write it as

I hope this helps!:)
Answer:
The largest side of given triangle is: AB
Step-by-step explanation:
In order to find the largest side, we have to find all the triangles first.
The two angles at point A will sum up to 180° as the angles on the straight line are supplementary.
So,

∠A = 44°
∠C = 71°
The sum of interior angles of a triangle is 180°
Using this:
∠A+∠B+∠C = 180°
44°+∠B+71° = 180°
∠B+115° = 180°
∠B = 180°-115°
∠B = 65°
In a triangle, the side opposite to the largest angle is the largest. In the given triangle, ∠C is the largest so the side AB which is opposite to ∠C is the largest.
Hence,
The largest side of given triangle is: AB