Due to the equal area

You can list:

(x-4)(y+4)=xy

(x +6)(y-2)=xy

Solution: x=9

y=5

The length of the rectangle is 9 cm; The width is 5 cm.

2。

1)(2700-2000)+(2 100- 1600)= 12000

700X+500Y= 12000

Simplified as: 7x+5y= 120.

When y is the smallest, x is the largest, and y = (0, 1, 2, 3, 4 ...)

It is found that when y=3, x is an integer. X= 15.

The maximum number of a color TV may be 15.

2) Yes.

Scheme 1: (1+30%) × (700-100) x+(1+40% )× (500-80) y.

Scheme 2: (1+50%) × (700-150)+(1+50% )× (500-80) y.

Namely: (1+30%) × 600x+(1+40%) × 420y.

( 1+50%)×550 x+( 1+50%)×420y

Higher than that in January

To sum up:

Both strategies can increase profits in February.