Hilda has $210 worth of $10 and $12 stock shares.
The number of $10 shares is five more than twice the
number of $12 shares. How many of each type of share
does she have?
Let n and v represent the numbers of $10 and $12 shares Hilda owns. .. n = 2v +5 . . . . . the number of $10 shares is 5 more than twice the number of $12 shares .. 10n +12v = 210 . . . Hilda has $210 worth of $10 and $12 shares
Using the expression of the first equation to substitute into the second, we have .. 10(2v +5) +12v = 210 .. 32v +50 = 210 . . . . . . collect terms .. 32v = 160 . . . . . . . . . . subtract 50 .. v = 5 . . . . . . . . . . . . . . divide by 32 .. n = 2*5 +5 = 15