Answer:
1020 students
Step-by-step explanation:
Given the trend line equation :
y = 0.1x + 18,
where y is the total number of staff members and x is the total number of students.
Using the equation, the predicted number of students in a school with 120 staffs ;
y = 120
y = 0.1x + 18
120 = 0.1x + 18
120 - 18 = 0.1x
102 = 0.1x
x = 102 / 0.1
= 1020 students
Answer going from left to right, top to bottom
47,77,20,31,78
84,60,72,11,47
60,96,99,11,19
14,39,76,93,77
For a better understanding of the solution provided here please find the relevant diagram drawn as per given information in the file attached.
As given,
. Also, it is given that
is a straight angle. Therefore,
.
As can be clearly seen from the diagram, if
and
, then:

Therefore, 
Hence Proved.
Answer:
(4 + y)(4 - y)
Step-by-step explanation:
