The right ans is D.I am 100%sure.
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Answer:
The solution is given below:
Step-by-step explanation:

As we know the value of k and r so the equation will be





Answer:
d
Step-by-step explanation:
The general term is obtained by starting with the initial value 5 and then subtracting 4 each time you wish to generate a new term:
a2 = second term = 5+(2-1)(-4) = 5+(-4) = 1
General term:
an = nth term = 5+(n-1)(-4)
Thus, the 21st term is 5+(21-1)(-4) = 5 + (20)(-4) = -75 (answer)