Question 80671
let x=cost of chocolate bars
and y=cost of gum

Now we are told that 3x+y=$1.75-------------------------eq1

We are also told that 2x+4y=$2.00-------------------------eq2

Multiply each term in eq1 by 4 and we get:

12x+4y=$7-----------------------------------------new eq1

Subtract eq2 from new eq1 and we have:

10x=$5  divide both sides by 10
x=$0.50----------------------------------cost of chocolate bars

substitute  x=$0.50 into eq 2:

2($0.50)+4y=$2  get rid of parens
$1+4y=$2  subtract $1 from both sides

4y=$2-$1
4y=$1  divide both sides by 4
y=$0.25-----------------------------------------cost of gum

CK

3($0.50)+$0.25=$1.75
$1.75=$1.75
and
2($0.50)+4($0.25)=$2
$2=$2

Hope this helps-------ptaylor