Solve this:
so let the length be 3x+y and let the breath be 7x+2y
the formula of perimeter of a rectangle is 2(L+B)
= 2(3x+y+7x+2y)
=2(10x+3y)
=20x+6y
thus 20x+2y is the perimeter
the formula of perimeter of a rectangle is 2(L+B)
= 2(3x+y+7x+2y)
=2(10x+3y)
=20x+6y
thus 20x+2y is the perimeter