Question 890289
w and L for original rectangle.
L-w=7 for this original rectangle.
L=w+7.
area is wL.
area is w(w+7).


New rectangle.
L-4 and w+3 become new length and breadth.
area is (L-4)(w+3).
This area again using the expression for L as earlier, is (w+7-4)(w+3),
which is (w+3)(w+3), the "new" area.


These areas were given as EQUAL.
{{{w(w+7)=(w+3)^3}}}
Simplify and solve for w.
{{{w^2+7w=w^2+6w+9}}}
{{{7w=6w+9}}}
{{{highlight(w=9)}}}
Compute L from the earlier described formula.
{{{L=w+7}}}
{{{L=9+7}}}
{{{highlight(L=16)}}}
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Now you can calculate the perimeter of the original rectangle because you know the values for w and L.
{{{p=2w+2L}}}
p=2*9+2*16
p=18+32
p=50----------------the answer