Question

help
solve 8 9 10
they are 5 mark questions​

Answer 1

A1=18

A2=13

A3=5

A4=3in ap terms

Answer 2

Step-by-step explanation:

8) an=a+(n-1)d

50=5+(n-1)3

45=(n-1)3

n-1=15

n=16

Sn=n/2(a+an)

Sn=16/2(5+50)

Sn=8×55

Sn=440

9) a2=a+(n-1)d

13=a+(2-1)d

13=a+d ....(1)

a4=a+(n-1)d

3=a+(4-1)d

3=a+3d ....(2)

By solving 1 and 2 we get a=18 d=(-5)

a1=a=18

a3=a+(n-1)d

a3=18+(3-1)(-5)=8