Answer:
see below
Explanation:
We want x² - 100.
We are adding these two binomials. Already we should recognize that adding these will not result in x².
–No–
We want to expand the binomial first.
(x - 9)(x - 9) - 19
Multiply using FOIL.
(x² - 9x - 9x + 81) - 19
Simplify.
x² - 18x + 81 - 19
x² - 18x + 62
–No–
Distribute the x.
x² - 100x
–No–
FOIL
x² - 10x + 10x - 100
Simplify.
x² - 100
–Yes–