Question

The sum of first 30 terms of an arithmetic sequence is 1830 if the common difference of the sequence is 4 find the first term

Answer 1

Answer:

S30=1830

C.D=4

as well know that,

S30=30/2{2a+29*4}

1830=15(2a + 116)

1830/15=2a+116

122=2a+116

122-116=2a

6=2a

6/2=a

3=a

Answer 2

Answer:

first term is 3

Step-by-step explanation:

s30= 30/2[2a+29×4]

=15[2a+116]

=30a+1740

1830=30a+1740

1830-1740=30a

90=30a

a=3