Question

the 6 and 7 terms of an ap are 21 and 54 respectively find the 40 term​

Answer 1

Answer:

1143

Step-by-step explanation:

In an AP, the nth term is given by,

$tn = a + (n - 1)d$

Where a is the first term and d is the common difference.

Given that the 6th term is 21,

21 = a + 5d (1)

Given that the 7th term is 54,

54 = a + 6d (2)

Solving the linear equations, by subtracting (1) from (2),

d = 54 - 21 = 33

Substitute the value of d in (1),

21 = a + 5(33)

a = -144

We are having the values of a and d, hence we can find the 40th term,

t40 = -144 + 39( 33 )

t40 = 1143

Hence, the 40th term in the AP is 1143.

Answer 2

Answer:

Step-by-step explanation:the 6&10 term of AP is -10&-26.find the of 15term