The first term of an arithmetic sequence is 1.2, and the eighth term is 9.6. Find its tenth term

The first term of an arithmetic sequence is 1.2, and the eighth term is 9.6. Find its tenth term

If the sequence is an and the tolerance is D, then
7d=a8-a1=8.4
d=1.2
So A10 = a1 + 9D = 12