Given sequence:
-2,-7,-12 ,..
Unknown;
Find the sum of the first 20 terms = ?
Solution:
The sequence is -2,-7,-12 ,..
To find he sum of n-terms of a sequence, we use the expression below;
Sₙ = 
where n is the number of terms = 20
a is the first term = -2
d is the common difference= -7 - (-)2 = -5
Now input the parameters and solve;
Sₙ = 
Sₙ = 10(-4 + -5(19)) = 10(-99) = -990
The sum of the first 20 terms of the sequence is -990
Triangles: 2(1/2)*8*6=
Left side: 6*10 =
Right side: 8*10 =
Back side: 10*10 =
48 + 60 + 80 + 100 = 288cm^2
Answer:
I think this is the correct answer
Answer:
3874.5342
Step-by-step explanation:
9.63 divide by 100 = 0.0963
0.0963x40 234= 3874.5342