A=21 B=125 C=34
A= C-13
B=4C-11
A+B+C=180 (all angles of a triangle add to 180)
(C-13)+(4C-11)+C=180
6C-24=180
6C=204
C=34
34-13=21=A
4×34-11=125=B
Let a₁ = the first number.
Because each number is 4 more than the number before it, the list of numbers forms an arithmetic sequence with a common difference of d = 4.
The n-th term is
The 200-th term is
a₂₀₀ = a₁ + (200 - 1)*4
= a₁ + 796
a₂₀₀ - a₁ = 796
Because a₂₀₀ is the last number on the list, the difference between the first and the last number on the list is 796.
Answer: The difference is 796.
It is C. 498.83 units cubed.
Hope I helped? ^ω^