Question 234434
Ok so lets say that Andy has x quarters and y half dollars.
So {{{x+y=14}}}
And now for the values of the coins.
{{{0.25*x+0.5*y=4.25}}} Each quarter is worth 0.25 and you multiply by x, and each half dollar is worth 0.5 and you multiply by y. When you add them up you get the amount the coins are worth.
So {{{x=14-y}}}
Putting this into the second equation gives us.
{{{0.25(14-y)+0.5y=4.25}}} Distributing the 0.25 gives us.
{{{3.5-0.25y+0.5y=4.25}}} Combine like terms.
{{{0.25y+3.5=4.25}}} Subtract 3.5 from both sides.
{{{0.25y=0.75}}} Divide both sides by 0.25.
{{{y=3}}} We now know that {{{y=3}}} and we can plug this into {{{x=14-y}}} to gives us {{{x=14-3=11}}}
So {{{y=3}}} and {{{x=11}}}