Answer:

Step-by-step explanation:
Given
See attachment for diagram
Required
The equation to find x
First, calculate the area of the big rectangle using:

So:

The smaller rectangle

The difference between this areas give the area of the shaded region.
So:


Open brackets

Collect like terms


<em>The above equation can be used to solve for x</em>
The answer is 80 because you add then subtract
1) 0.78
2) 34.28
This is because the number in the 3rd decimal place for both numbers is 5 or above so it is rounded up rather than down.