Question

If 4x,x+12,5x+3are in AP , find the value of of x

Answer 1

these are in a.p. so

first term = 4x
second term=x+12
third term=5x+3
so as we know
d= second term - first term
d= x+12-4x
d=12-3x.....(1)
now,
d=third term -second term
d=5x+3-(x+12)
d=5x+3-x-12
d=4x-9 ......(2)

from equation 1 and 2
12-3x=4x-9
12+9=4x+3x
21=7x
x=21/7
x=3

Answer 2

Answer:

           x = 3

Step-by-step explanation:

Since,

b = (a + c)/2 ------------ (1)

a = 4x

b = x + 12

c = 5x + 3

Substitute those a,b,c values in the above equation,

x + 12 = (4x + 5x + 3) / 2

2(x + 12) = (9x + 3)

2x + 24 = 9x + 3

Take numbers one side and constant one side,

9x - 2x = 24 - 3

7x = 21

x = 21/7

Therefore,

x = 3

Hope it helps U