Answer:
The value of x is 5.
Explanation:
Given that:
Base of triangle = b = x
Length of side of triangle = a = 4x-3
Perimeter = 39
In an isosceles triangle, two sides of the triangle are equal.
Perimeter of an isosceles triangle is given by,
P = 2a+b
Putting the values
39 = 2(4x-3)+x
39=8x-6+x
39=9x-6
39+6=9x
45=9x
9x=45
Dividing both sides by 9

Hence,
The value of x is 5.