Answer:
x = 20
Explanation:
Given the triangles are congruent then corresponding angles are congruent, so
∠ N = ∠ E
To calculate ∠ E subtract the sum of the 2 given angles from 180
∠ E = 180 - (x - 5 + 4x - 10)
= 180 - (5x - 15)
Equate ∠ N and ∠ E
5x - 5 = 180 - 5x + 15 ( add 5x to both sides )
10x - 5 = 195 ( add 5 to both sides )
10x = 200 ( divide both sides by 10 )
x = 20