Answer:
49 - x^2
Explanation:
(7+x)(7-x)
We know this is the difference of squares
(a-b) (a+b) = a^2 - b^2
7^2 - x^2 = 49-x^2
We can also FOIL
first = 7*7 = 49
Outer: = 7x
Inner: = -7x
Last : -x*x = -x^2
Add them together
49 +7x-7x - x^2
Combine like terms
49-x^2