Answer:
x = 12
Step-by-step explanation:
The sum of a heptagon interior angles is 900 degrees, so:
10x + 5 + 12x - 9 + 9x + 14 + 133 + 10x + 9 + 10x + 136 = 900
rearrange to make it easier to subtract/add, u don't have to do this it's optional
10x + 12x + 9x + 10x + 10x + 5 - 9 + 9 + 14 + 133 + 136 = 900
add liket terms
22x + 29x + 19 + 269 = 900
51x + 288 = 900
subtract 288 from both sides
51x = 612
divide by 51
x = 12
