Answer:
x = 51
Explanation:
The figure shown is a pentagon
The angles in a pentagon add up to equal 540
Which means that 77 + 107 + 156 + 149 + x = 540
^ ( note that we just created an equation that we can
use to solve for x )
We then solve for x using that equation
77 + 107 + 156 + 149 + x = 540
step 1 combine like terms
77 + 107 + 156 + 149 = 489
we now have 489 + x = 540
step 2 subtract 489 from each side
489 - 489 cancels out
540 - 489 = 51
we're left with x = 51