Question

Find the middle term of ap -11,-7,-3......,49

Answer 1

Answer:

17 and 21

Step-by-step explanation:

hope this helps you

Answer 2

Question:

Find the middle term of ap -11,-7,-3......,49.

Answer:

The middle terms are 17 and 21 .

Step-by-step explanation:

-11,-7,-3......,49

$a \: (first \: term) = - 11$

$d \: (common \: difference) = t_{2} - t_{1}$

$t_{2} = - 7 \\ t_{1} = - 11$

$d = - 7 - ( - 11)$

$\boxed{d = 4}$

$l \: (last \: term) = 49$

$n \: (no.of \: terms) = \frac{l - a}{d} + 1$

$n = \frac{49 - ( - 11)}{4} + 1$

$n = \frac{60}{4} + 1$

$n = 15 + 1$

$\boxed{n = 16}$

The middle terms are 8 and 9

$t_{n} = a + (n - 1)d$

$t_{8} = a + 7d$

$t_{8} = - 11 + 7(4) = - 11 + 28$

$\boxed{t_{8} = 17}$

$t _{9} = a + 8d$

$t _{9} = - 11 + 8(4) = - 11 + 32$

$\boxed{t _{9} = 21}$

Therefore the middle terms are 17 and 21 .