What's the expression of the square and the length is 7x-3

Question

The length is 7x-3 and I need the expression for the area

Answer 1

If you mean that the side of a square is (7x-3), then the area is that expression, squared.

 

THIS IS SQUARING A BINOMIAL.  THE PATTERN WHICH EVERYONE WHO TAKES ALGEBRA MUST KNOW (MEMORIZE!):

(a-b)² = a²  - 2ab + b²

 

Note the formation of the middle term: the product of the two parts, and 2, with the - sign preceding it.

 

All you have to do is to substitute a= (7x), b = 3.