Question

A square with a side of y is transformed into a rectangle by adding 10 to one side and then subtracting 10 from another. Express the new area as a polynomial

Answer 1

Answer: $y^2-100.$

Step-by-step explanation:

if we have a square with sides 'y' units,

then, its breadth = length = y

If we add 10 to one side it will become (y+10)  (longer one) and subtract 10 from another, then it will become (y-10) (shorter one).

Area of rectangle = breadth x length

So, area of rectangle $= (y+10)(y-10)$

$= y^2-10^2=y^2-100\ \ \ \ \ [(a-b)(a+b)=a^2-b^2]$

Hence, the new area as a polynomial = $y^2-100.$