x/3 - 1/x = 2/3find a common denominator: 3x(x*x)/3x - (1*3)/3x = 2/3(x2-3)/(3x) = 2/3(x2-3)*(3) = (3x)*(2)3x2-9 = 6x3x2-6x-9 = 0x2-2x-3 = 0(x-3)(x+1)=0x-3=0 & x+1=0x=3 & x=-1
Depends on your definition of "Sets of Coins"if this means combinations of units of currency the answer is Two (2):1) 6 quarters = 1.502) 5 quarters, 2 dimes, and 1 nickel = 1.50if each individual coin is treated as a unique item then option 2 becomes 36 different options:6 different quarters could be excluded3 different dimes could be excluded2 different nickels could be excludedfor 6x3x2 = 36 combinations +1 (the 6 quarter method)=37 sets of coins.