Answer:
Step-by-step explanation:
These binomials make up the difference of squares.
3x * 3x = 9x^2
3x * 5 = 15x
-5 * 3x = - 15x
-5 * 5 = - 25
Notice the 2nd and 3rd terms. They are equal except that one is plus and the other minus. That means they cancel. You are left with
9x^2 - 25
