Since x is our unknown number, on one side of our equation we will have the "<span>Subtracting two times a number from 10", and on the other will be -3. So,
-3=10-2x</span>
First term [ a ] = 6.3
Common difference [ d ] = 8.8 - 6.3 = 2.5
Using general term formula,
78.8 = 6.3 + (n-1)*2.5
2.5*(n-1) = 72.5 [ Dividing both sides by 2.5 ]
n-1 = 29
n = 30
Hence, 78.8 is the
30th term in the arithmetic series.