Anxiety Disorder Statistics. Anxiety Disorders affect 18.1 percent of adults in the United States (approximately 40 million adults between the ages of 18 to 54).
Perfect square. Perfect square is an element of algebraic structure which is equal to the square of another element. Square number, a perfect square integer.
If you did not see the common factor, you can begin with observing the perfect squares. Both 4y2 and 36y6 are perfect squares (their coefficients are perfect squares and their exponents are even numbers). Since subtraction is occurring between these squares, this expression is the difference of two squares.