A ballroom has a square dance floor. The area of the floor is 400 square feet. If the length of each side of the square increased by one foot, would its area be a rational number?
Choose all that apply.
Answers:

A. - The area of the floor would be a rational number.

B. - The area of the floor would be an irrational number.

C. - Each side length would be a perfect square.

D. - The area of the floor would be a perfect square.

E. - The area of the floor would be a nonterminating, nonrepeating decimal.

D

Step-by-step explanation:

Area of square=400sq.ft

or,l²=400sq.ft

or,l=(400sq.ft)½

or,l=(20²sq.ft)½

or,l=20ft

Thus,length of square is 20ft.

If length of square is increased by 1 ft then ,

New length=(20+1)ft=21ft

Area of square=(21ft)²

=441sq.ft

answer: (-6,3)

step-by-step explanation:

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.