Step-by-step explanation:
This is a right triangle which means one of the angles is 90° and since the sum of interior angles in a triangle is equal to 180 then the sum of two other angles must be 90
7x + 6 + 6x - 7 = 90 add like terms
13x - 1 = 90 add 1 to both sides
13x = 91 now divide both sides by 13
x = 7 to find each angle replace x with 7
7x + 6 = 7×7 - 6 = 55° and
6x - 7 = 6×7 - 7 = 35°
