Arectangle has a perimeter of 60 cm let x represent the length of one side of the rectangle which of the following functions models the area a(x) of the rectangle?

a. a(x) = x^2 + 30x
b. a(x) = 30x - x^2
c. a(x) = x^2 + 60x
d. a(x) = 60x - x^2

B.

Step-by-step explanation:

P(x)= 2( x+y)  //Rectangle perimeter              =>   A(x)= xy         //Rectangle area

60 = 2(x+y)                                                                   =x(30-x)  //Substituting y            

60/2= [2(x+y)]/2                                                            =30x - x²

  30= x+y

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.