How do you solve this ?

Question

Answer 1

A = (x + 2)(x - 2) = 45 cm^2

x^2 = 49

x = 7 cm

Answer 2

Apply the exact same reasonning given to you in

https://ca.answers.yahoo.com/question/index?qid=20...

Looks like that you are not even trying. 

Hopefully no one will spoil you the answer. That would be very irresponsible of them. 

Answer 3

(x+2)(x-2) = x^2 - 4 = 45

x^2 = 49

x = 7, discard -7

Answer 4

Area = (x+2)cm (x-2)cm = 45 cm²

            x² - 4 = 45

            x² = 49

            x = 7 cm ...............ANS