Question

2) For a given A.Pt7 = 4, d = 4 then a =
(a) 6
(b) 7
(c) 20
(d) 28​

Answer 1

Given :-

7th term of AP = 4

Common difference = 4

Solution :-

t7 = a + ( n - 1 )d = 4

Put the required values in the formula ,

t7 = a + ( 7 - 1 )4 = 4

a + 28 - 4 = 4

a + 24 = 4

a = 4 - 24

a = -20

Hence , The value of a = -20

Related Formulas : -

• a + ( n - 1)d

Here , a is first term , n is no .of terms and d is common difference

• n/2 ( 2a +( n - 1)d )

Here, n is no. of terms , a is first term d is common difference .