Step-by-step explanation:

point 1 ( -7,y)
point 2 (1,13)




y = 7
I)
8 - 3x = 23
-3x = 15
x = -5
ii)
5x - 16 = 34
5x = 50
x = 10
iii)
2 - 5x = -3
-5x = -5
x = 1
A6 = -8
a15= -62
There are (15 - 6) terms in between, therefore 9 terms in between.
-8 to -62 ... there is a difference of 54
54 ÷ 9 = 6
Therefore it gets -6 each term.
a6 = -8, a7= -14, a8 = -20 ......