Answer:
6
Step-by-step explanation:
7 x 6 = 42 + 9 = 51 + 54 = 105 + 75= 180
Tge sum of interior angles in a triangle is equal to 180°
7x + 9 + 54° + 75° = 180° add like terms
7x + 138° = 180° subtract 138 from both sides
7x = 42 divide by 7
x = 6
