Answer:
x = 3
Step-by-step explanation:
Using the triangle similarity theorem
x/x+3 = x+3/12
Cross multiply
12x = (x+3)(x+3)
12x = x²+3x+3x+9
12x = x²+6x+9
x²+6x+9-12x = 0
x²-6x+9 = 0
Factorize
x²-3x-3x+9 = 0
x(x-3)-3(x-3) = 0
x - 3 = 0
x = 3 twice
Hence the value of x is 3
