Answer:
x = 15
Explanation:
The sum of the four angles of a quadrilateral add up top 360°
Given:
m∠A = (5x+14)°
m∠b = 109°
m∠C = (3x+8)°
m∠D = 109°°
Here we are given actual values for two angles as 109°. Their sum is: 109 + 109 = 218°
The sum of the remaining two angles which are expressions in x should be:
360 - 218 = 142°
This is the sum of m∠A an m∠C
Substituting the terms for the two angle measures we get
(5x+14) + (3x+8) = 142
5x+14 + 3x+8 = 142
Grouping like terms:
5x + 3x + 14 + 8 = 142
8x + 22 = 142
8x = 142- 22
8x = 120
x = 120/4
x = 15