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:
-10 and 8 multiply them to equal 80 but if there both negative it will be a positive 80 because if you multiply 2 negatives its postive hope this helps