Question

What is the closed linear form of the sequence 5, 7.5, 10, 12.5, 15,..?

Answer 1

first term =a1=5
common difference=7.5-5=10-7.5=2.5

so an=a1+(n-1)d

so
an=5+(n-1)*2.5
an=5+2.5n-2.5

an=2.5+2.5n