Area=legnth times width=31 the frame must go around the frame with equal legnth, x so the total area (meaning the frame +picture) is 5+x by 6+x 31=(5+x)(6+x) expand 31=30+11x+x^2 minus 31 both sides 0=-1+11x+x^2 x^2+11x-1=0
To begin, each of the friends have made 4 bags of dough. This gives 12 bags at the outset. After 10 days, all 12 bags are made into (4*12) bags, or 48 bags. After 20 days, the 48 bags are made into (48*4), or the required 192 bags. After 20 days, then, the friends have the needed 192 bags.