Answer:
x = 25
Explanation:
Internal angles of a triangle = 180 degrees
So knowing this we can form the following equation
(x + 26) + (x + 14) + (4x - 10) = 180
Simplify
(x + x + 4x) + (26 + 14 - 10) = 180
6x + 30 = 180
Rearrange for x
6x = 180 - 30
6x = 150
x = 25