Question

a3=18, a7=30 find a and d also find the AP with 4terms​

Answer 1

Answer:

Here

Step-by-step explanation:

Here d = 3

a = 12

a4 =21

Answer 2

Q3=18

A7=30

S17=?

a+2d=18-----(1)

a7=a+2d=18-----(2)

on subtracting (1)and(2),we get -4d= -12

d=3

putting the value d in equaction (1),we get

a+2d=18

a+2(3)=18

a+6=18

a+18-6

a=12

and a=12 &d=3

S17=n/2(2a+(n-1)d)

S17=17/2(2(12)+(17-1)(3)

S17=17/2(24+48)

S17=612