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