Question 1208792
<font color=black size=3>
{{{
drawing(400,400,-4,4,-4,4,
line(-3,1,3,1),line(3,1,3,-1),line(3,-1,-3,-1),line(-3,-1,-3,1),line(1,-1,1,1),
locate(-3.52,0.22,"y"),locate(3.52-0.3,0.22,"y"),locate(-1.22,1.44-0.1,"x"),locate(1.78,1.58-0.1,"100"),locate(-1.22,-1.44+0.3,"x"),locate(1.78,-1.58+0.5,"100"),locate(-1.62,0.18,"original"),locate(1.7,0.16,"extra")
)
}}}
The original runway is the rectangle on the left.
The added part is the rectangle on the right which has an area of <font color=red>100*y square feet</font>.
For example, if y = 15 then 100*y = 100*15 = 1500 square feet has been added.
But since we don't know the value of y, we leave the expression 100y as it is.


Answer: <font color=red>100y</font>
</font>