Question

The first two terms of an AP are -5and 4. The 21st term of the A.P. will be :

Answer 1

Answer:

Hope this answer helps you

Answer 2

The 21st term of the A.P. will be 175

• Let the first term of the AP is a and common difference is d.
• It is given that a = -5 and a+d = 4. So we can find d = 4-a = 4-(-5) = 4+5 = 9

• Now the 21st term of the AP is $t_{21} = a+(21-1)d = a+20d = -5 + 20*9 = -5+180 = 175$

• So we get the desired term of AP as 175.