Question

Question 25 (or ↑) and 26 (or ↓). The questions are marked by pencil.

Answer 1

26. let the 4 consecutive ap are a-3d , a-d, a+d , a-3d.

now,

a-3d + a-d+ a+d + a-3d. =32

4a. = 32

a = 8

now,

(a-3d) (a+3d.). 7

–------------------- = ----

(a-d) (a+d). 15

a^2 -9d^2. =. 7

–------------------- = ----

a^2 -d^2. 15

15(64 -9d^2). = 7(64 -d^2)

960 - 135d^2. = 448 -7d^2

512. =128 d^2

d. = ±2