What value of p are

2p-1,7 and 3P three consecutive terms of ARITHMETIC PROGRESSION

2 answers

What value of p are 2p-1, 7 and 3p three consecutive terms of an ARITHMETIC PROGRESSION?

Letting a = the common difference, we can write
1--(7 - a) = 2P - 1 and
2--(7 + a = 3p

Adding yields 14 = 5p - 1 from which p = 3 making the 3 terms 5, 7 and 9.
figer math for 2nd grade