Answer:
10
Explanation:
To find the value of x, create a proportion. A proportion is two equal ratios for similar figures. The two triangles are similar because they are the same shape but not the same size. Create ratios between corresponding sides of figures.
To solve for x, cross multiply:
12(x+4) = (2x+1)(8)
12x + 48 = 16x + 8
48 = 4x + 8
40 = 4x
10 = x