Answer:
x = 20
Step-by-step explanation:
The triangles are similar
3 (3+5)
----- = ----------
12 (12+x)
Using cross products
3(12+x) = 12*(3+5)
3(12+x) = 12*8
3(12+x) = 96
Divide by 3
3(12+x)/3 = 96/3
12+x = 32
Subtract 12
12+x-12 =32-12
x = 32-12
x =20
