## College Algebra (11th Edition)

16$x^{4}$ - 25$y^{2}$
1. Product of the sum and difference of two terms: (4$x^{2}$ - 5y)(4$x^{2}$ + 5y) = $(4x^{2})^{2}$ - $(5y)^{2}$ 2. Solve exponents with power rules 16$x^{4}$ - 25$y^{2}$