Question

The 11th term of an AP is -7 while the 3rd term is 9,find the first four terms

Answer 1

Answer:

13, 11, 9, 7

Step-by-step explanation:

tn = a + (n-1)d

∴ t₁₁ = a + 10d

-7 = a + 10d    → Equation 1

tn = a + (n-1)d

∴t₃ = a + 2d  

9 = a + 2d    →Equation 2  

On equating equation 1 and 2, we get a = 13 and d = -2

Using the formula tn = a+ (n-a)d,

we get

t₁ = 13

t₂ = 11

t₃ = 9

t₄ = 7