198,983 views
38 votes
38 votes
8x - 10
25
B
E
18
15
с
D
Solve for x

8x - 10 25 B E 18 15 с D Solve for x-example-1
User Pouya
by
2.9k points

1 Answer

28 votes
28 votes

Explanation:

the upper (smaller) triangle and the complete triangle are similar.

that means the angles in both triangles are the same. and the lengths of all corresponding pairs of sides correlate with the same scaling factor.

therefore,

(8x - 10) / (8x - 10 + 18) = 25 / (25 + 15)

(8x - 10) / (8x + 8) = 25 / 40 = 5/8

8(8x - 10) = 5(8x + 8)

64x - 80 = 40x + 40

24x = 120

x = 5

User Tarun Gaba
by
3.2k points