## Algebra 1

a) $x+y =15$ $.01x+.25y = 4.35$ $x=-2.5$, $y=17.5$ b) No, it's not reasonable. You can't have a negative number of coins (or half of a coin).
$x+y =15$ $.01x+.25y = 4.35$ $x+y =15$ $x+y-x =15-x$ $y = 15-x$ $.01x+.25y=4.35$ $.01x+.25*(15-x)=4.35$ $.01x+3.75-.25x=4.35$ $-.24x+3.75=4.35$ $-.24x+3.75-3.75=4.35-3.75$ $-.24x = .6$ $-.24x/-.24 = .6/-.24$ $x = -2.5$ $x+y = 15$ $-2.5 +y = 15$ $-2.5 + y + 2.5 = 15 +2.5$ $y= 17.5$