Answer:
cm
Step-by-step explanation:
We need to find the perimeter of the rectangular blanket in this case because a border is being sewn onto the blanket. The perimeter of a rectangle can be calculated by multiplying the sum of the rectangle's length and width by 2. As an algebraic expression, that would be , where
is the rectangle's length and
is the rectangle's width. We are given that
and
. Therefore,
cm of ribbon will be needed. Hope this helps!