Answer:
x = 9
Explanation:
Sum of a triangle is 180°.
6x + 1 + 6x - 14 + 9x + 4 = 180°
Arrange the like terms together and simply this equation.
6x + 6x + 9x + 1 + 4 - 14 = 180°
21x - 9 = 180°
Shifting '-9' to the other side of the equation gives you '+9'
21x = 180° + 9
21x = 189
Shifting 21 to the other side of the equation (to get x) makes it ÷21 (multiply)
x = 189 ÷ 21
x = 9