Answer:
x = 6
Step-by-step explanation:
Based on the triangle sum theorem, the sum of the interior angles of a triangle = 180°
Given the following, right angle (90°), 60°, and (7x - 12)° as interior angles of the triangle, therefore:
7x - 12 + 90 + 60 = 180
Add like terms
7x + 138 = 180
7x + 138 - 138 = 180 - 138 (subtraction property of equality)
7x = 42
7x/7 = 42/7 (division property of equality)
x = 6
