Question 218815
Let x = cost of the bike
x-73 = Mary's money
x-56 = Jane's money


The equation is based upon the fact that if you ADD their money together, the sum of their money is greater than or equal to the cost of the bike:


{{{x-73+x-56>=x}}}
{{{2x-129>=x}}}


Subtract x from each side:
{{{x-129 >=0}}}


Add 129 to each side:
{{{x>=129}}}


The cost of the bike is greater than or equal to $129.
If the bike costs $129, then Mary has x-73 or 129-73 = $56.
Jane has x-56 or 129-56 = $73.

As a checke, together they have $56 +$73 = $129, which is enough to buy the bike.  If the bike costs MORE than $129, then each girl has more than this amount.  


R^2


Dr. Robert J. Rapalje, Retired
Seminole State College of Florida