Where are the statements please?
The number of stamps with penny in terms of x is 
<em><u>Solution:</u></em>
Given that,
Ryan has x stamps in his collection
Number of stamps of Ryan = x stamps
Let the stamps with penny be "a"
Ryan has 6 times as many stamps as penny
Therefore,
Number of stamps in Ryan = 6 times as many stamps as penny

Thus number of stamps with penny in terms of x is 
Answer:
The area of one trapezoidal face of the figure is 2 square inches
Step-by-step explanation:
<u><em>The complete question is</em></u>
The point of a square pyramid is cut off, making each lateral face of the pyramid a trapezoid with the dimensions shown. What is the area of one trapezoidal face of the figure?
we know that
The area of a trapezoid is given by the formula

where
b_1 and b-2 are the parallel sides
h is the height of the trapezoid (perpendicular distance between the parallel sides)
we have

substitute the given values in the formula


This is the symmetric property, for you divide 9 to both sides to get x, instead of adding (addition property of equality)
So symmetric property should be your answer
Hope this helps