Answer:
18
Step-by-step explanation:
The factors of 72 are 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72
The factors of 18 are 1, 2, 3, 6, 9, 18
The common factors are 1, 2, 3, 6, 9, 18
The greatest common factor = 18
72 factors=1,2,3,4,6,8,9,12,18,24,36,72
18 factors=1,2,3,6,9,18
So HCF = 18
75?
1/4 = 25
25 x 3 =75
----
3/4=75
Algebra I believe
15
Rate of change or slope or gradient of a line passes two points (x1, y1) and (x2, y2) could be calculated by:
(y2 - y1)/(x2 - x1)
=> Rate of change of the line passing (1,15) and (3,45):
(45 - 15)/(3 - 1) = 30/2 = 15
