Hey: ) can you me posted picture of question

x² - 10x + 21

Explanation:
To answer this question, we will simply multiply each term from the first bracket by each term from the second and then combine like terms to get the final expression.

This can be done as follows:
(x - 3)(x - 7)
x(x) + x(-7) -3(x) -3(-7)
x² - 7x - 3x + 21
x² - 10x + 21

Hope this helps :)

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

Ican't do any of the other stuff, but i can get you started. the answer, i believe, is $2.50.