Answer:
3x=21
X=7
Step-by-step explanation:
Desmos.com and plug in the equation
Use the chain rule to compute the second derivative:

The first derivative is


Then the second derivative is


Then plug in π/4 for <em>x</em> :

<u>We are given:</u>
We know that the sum of all interior angles of a Pentagon is 540°
we are given 4 out of the 5 angles
<u>Solving for x:</u>
since the sum of all 5 angles is 540°:
75 + 130 + 135 + x + 90 = 540
x + 430 = 540
x = 540 - 430
x = 110°