Answer:
a₁ = 42
Step-by-step explanation:
The nth term of an arithmetic sequence is
[tex]a_{n}[/tex] = a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₅₀ = 140 and a₅₁ = 142 , then
a₁ + 49d = 140 → (1)
a₁ + 50d = 142 → (2)
Subtract (1) from (2) term by term to eliminate a₁
0 + d = 2
d = 2
Substitute d = 2 into (1)
a₁ + 49(2) = 140
a₁ + 98 = 140 ( subtract 98 from both sides )
a₁ = 42
