Answer:
T₁₀
Step-by-step explanation:
We know the first term is 21, which is a
We work out the difference by taking 21 away from 42 which equals 21.
We then use the general formula:
Tₓ = a + (x-1)(d)
We need to find the term which equals 210
210 = 21 + (x - 1)(21)
210 = 21 - 21 + 21x
210 = 21x
x = 10
Hence it is the 10 term when the thing equals 210.
