Question 358134
Let x be the sides of the original square piece of sheet metal.
4(x-2*4)^2=676
4(x-8)^2=676
4(x^2-16x+64)=676
4x^2-64x+256-676=0
4x^2-64x-420=0
4(x^2-16x-105)=0
(x-21)(x+5)=0
x-21=0
x=21 ans. for the side measurement of the sheet of metal.
Proof:
4(21-2*4)^2=676
4(21-8)^2=676
4*13^2=676
4*169=676
676=676