Ok, so to find the area you would times 2x - 5 like so
(2x -5) (2x - 5)
Then foil out the parenthesis
2x times 2x equals 4x^2
2x times -5 equals -10x
2x times -5 equals -10x
-5 times -5 equals 25
Therefore, your answer after foiling it out is 4x^2 - 20x + 25
Then to find the area when x=7, plug it into the problem.
4(7)^2 - 20(7) + 25
The answer would then be 81