Question

.Find the sum of the first 50 common terms of 12, 16, 20,.... and 18, 24, 30,....​

Answer 1

Answer:

Step-by-step explanation:

Sn=n/2{ 2a +(n-1)d}

n=50

a=12

d=4

sn=50/2[2(12) +(50-1)4]

Sn=25[24+196*4]

Sn=25[808

Sn=20,200

Answer 2

Answer:

5500,8250

Step-by-step explanation:

1) AP: 12,16,20

a50=a+49d

=12+49

=12+196

a50=208

S50=n/2(a+l)

=50/2(12+208)

=25(220)

S50=5500

Therefore sum 50 of terms in this APis 5500

2)AP:16,24,30

a50=a+49d

=16+49(6)

=16+294

a50=312

S50=n/2(a+l)

=25(16+312)

=25(330)

=8250

Therefore sum of 50 terms In this AP is 8250