Question

The sum of 5th and 9th terms A.P is 72 and the sum of 7th and 12th tern is 97.Find the A.P

Answer 1

A5 Plus A9 is equal to 72 and a 7 + 12 is equal to 97 so A5 Plus A9 is equal to 72

a + 4 d + a + 8 d is equal to 72

2A + 12 d is equal to 72 equation first

according to second equation a + 6d + a + 11d is equal to 97

2A + 17 is equal to 97 second equation

by using elimination method we get

5 d is equal to 25

d is equal to 5

put the value of the in equation first

show the value of a is equal to 6

hands DP is 6,11 ,17 ,23.............