Answer:
x = 9
Step-by-step explanation:
This problem involves knowing the sum of angles in a triangle as well as the sum of supplementary angles. In any triangle, the sum of all the angles will always add up to 180°. Supplementary angles add up to 180° and form a straight line. In order to solve for 'x', we must set up an equation where the sum of the angles is equal to 180°. Since the last angle of the triangle is not given, but we know that the value will be equal to 180 - (14x + 1), we can simplify this to 180 - 14x -1 or 179 - 14x. We also know that this angle plus the other two angles of the triangle will add up to 180:
89 + 179 - 14x + 5x - 7 = 180
Combine like terms: 261 - 9x = 180
Inverse operations: 261 - 261 - 9x = 180 - 261 or -9x = -81
Solve for x: x = 9
