Answer:
x = 21
Explanation:
Remember that the interior angles of a triangle always add up to 180°. Using this information, you can set up an equation to solve for x:
40 + x + (5x + 14) = 180
Add similar elements and combine like terms
6x + 54 = 180
Subtract 54 from both sides
6x = 180 - 54 = 126
Divide each side by 6
x = 126/6 = 21