Question

for an A.P t4 =20, t7=32 find a & d​

Answer 1

Step-by-step explanation:

t4 = 20

a+3d = 20(1)

t7= 32

a+6d=32 (2)

solve both as linear equation

subtract (2) by(1)

a+6d=32

a+3d = 20

0+3d= 12

d= 4

substitute d=4 in (1)

a+3d = 20

a=8

now u can easily find tn by putting formula for tn

i. e

tn= a+(n-1) d

Answer 2

Answer: The answer a=12.2 and d=2.6

HOPE THIS HELPS