need help with this!

Answer:
The sum of the interior angles of any triangle = 180°
Step-by-step explanation:
(15x + 1) + (6x + 5) + (4x – 1) = 180°
25x + 5 = 180
25x = 175
x = 7
Evaluate x into each: m<A = 106° , m<B = 47° , m<C= 27°
106 + 47 + 27 = 180