Answer:
The common difference (or common ratio) = 0.75
Step-by-step explanation:
i) let the first term be
= 80
ii) let the second term be
=
. r = 80 × r = 60 ∴ r =
= 0.75
iii) let the third term be
=
. r = 60 × r = 45 ∴ r =
= 0.75
iv) let the fourth term be
=
. r = 45 × r = 33.75 ∴ r =
= 0.75
Therefore we can see that the series of numbers are part of a geometric progression and the first term is 80 and the common ratio = 0.75.
7x - 3 = 5x + 5
-5x -5x
2x -3 = 5
+3 +3
2x = 8
x = 4
36/3= 12
12(12)= 144/2= 72
The area of the triangle is 72 square cm.
Hope this helps!