Answer:
The value of x is 10.5 units.
Step-by-step explanation:
Given:
ABCD is a parallelogram.
AB = 
BC = 
CD = 
We need to find the value of x.
Now the Definition of Parallelogram states that;
"A parallelogram is a quadrilateral with two pairs of parallel sides. The opposite sides of a parallelogram are equal in length and the opposite angles are equal in measure."
Hence from Above definition we can say that;
since these are the opposite sides of parallelogram.
Now Substituting the given values we get;

Now solving the equation we get;
Combining the like terms first.

Now using addition and subtraction property of equality we get;

Now using Division Property we will divide 2 on both side we get;

Hence the value of x is 10.5 units.