Question

For $7.52, you purchased 8 pens and highlighters from a local bookstore. Each highlighter costs $1.09 and each pen costs $.69. How many pens did you buy?

Answer 1

p=number of pens
h=number of highlighters

p+h=8

1.09h+0.69p=752


p+h=8
minus h from both sides
p=8-h

sub that for p

1.09h+0.69(8-h)=7.52
1.09h+5.52-0.69h=7.52
0.4h+5.52=7.52
minus 5.52 from both sides
0.4h=2
divide both sides by 0.4
h=5

sub back

h=8-p
5=8-p
minus 8 frm both sides
-3=-p
mltiply both sides by -1
3=p



3 pens you bought