Question 575162
A square plywood platform has a perimeter which is 8 times the length of a side, decreased by 28. Find the length of a side 
sol:
 side = x
by formula, perimeter = 4x ----(1)
given perimeter = 8*x - 28 -----(2)
 equate 1 & 2
 you will get x = 7 units.