Question

A square piece of fabric has an area of 16x^2+40x+25 square inches. The length of each side of the fabric is cx+d, where c and d are whole numbers. Find an expression in terms of x for the perimeter of the piece of fabric. Then find the perimeter when x=2.

How would I do this?

Answer 1

Draw a square, label the side (cx+d). What is the area of the square in terms of c and x and d?

Answer 2

cxd

Answer 3

Nope, for a square with side s, the area is s*s, or s^2.

So now we have a square with side (cx+d). What is its area?

Answer 4

6x^2+40x+25

Answer 5

Yes

Answer 6

No, the area of a square of size (cx+d) is (cx+d)*(cx+d).

And that value is equivalent to (c^2)*x^2 + c*d*x + c*d*x + d^2. Does that make sense?

Answer 7

So if the area (c^2)*x^2 + (2*c*d)*x + d^2

if equal to 6x^2+40x+25, then you should be able to solve for c and d.

Answer 8

alright

Answer 9

thanks