Answer:
[tex]7000[/tex]
Step-by-step explanation:
Recall the form of the difference of squares.
[tex]x^2 - y^2 = (x+y)(x-y)\\\\\\[/tex]
Now let's apply it to your numbers:
[tex]85^2 - 15^2 = (85 + 15)(85 - 15)[/tex]
Simplify:
[tex](100)(70) = 7000[/tex]
