Question

4. The value of x for which 3x , (x + 8) and (5 x + 2) are three consecutive
terms of an AP is
a) 7/3
b)7/3
c)3/7
d) -3/7​

Answer 1

Answer:

x = 7/3

Step-by-step explanation:

Lets consider 1st, 2nd and 3rd terms of AP be 3x, (x + 8) and (5 x + 2)

a = 1st term = 3x

d = common difference = 2nd term - 1st term

= x + 8 - 3x = 8 - 2x

Tn = a + ( n - 1 ) d

=> T3 = 3x + ( 3 - 1 ) ( 8 - 2x )

=> 5x + 2 = 3x + 2( 8 - 2x )

=> 5x + 2 = 3x + 16 - 4x

=> 5x + 2 = 16 - x

=> 5x + x = 16 - 2

=> 6x = 14

=> x = 14/6 = 7/3

Answer 2

Answer:

3x, (x+8), (5x+2)

a1=3x, a2=(x+8), a3=(5x+2)

a2-a1=a3-a2

(x+8)-3x=(5x+2)-(x+8)

x+8-3x=5x+2-x-8

8-3x+x=5x-x-8+2

8-2x=4x-6

(-2x)-4x=(-6)-8

(-6x)=(-14)

6x=14

x=14/6

x=7/3