(х+1)(х-1)+7

The expression you've written can be simplified by expanding the multiplication and then adding the 7.

First, let's use the distributive property to expand the multiplication of the two binomials:

(х + 1)(х - 1) = х^2 - х + х - 1

Notice that the -х and the +х in the middle will cancel each other out:

х^2 - х + х - 1 = х^2 - 1

Then we add the number 7 to the simplified form of the multiplication:

х^2 - 1 + 7 = х^2 + 6

Thus, the expanded and simplified form of the expression (х+1)(х-1)+7 is х^2 + 6.