How do you simplify #(9 - sqrt2) (7 + sqrt2)#?

1 Answer
May 20, 2016

Answer:

#61+2sqrt(2)#

Explanation:

First, to simplify this expression, you need to use the distributive property (or FOIL):
#(9-sqrt(2))(7+sqrt(2))#
#9(7)+9(sqrt(2)) -sqrt(2)(7) -sqrt(2)(sqrt(2))#
#63+9sqrt(2) -7sqrt(2) -sqrt(4)#

Now, you simplify:
#63+2sqrt(2)-2#
#63-2+2sqrt(2)#
#61+2sqrt(2)#