12 pencils and 6 pens cost 120 $.
The price of 2 pens is more by 5 $ than the price of 3 pencils.How many $ does cost a pencil and a pen?
2006-06-07 22:56:13 · 7 answers · asked by morena_shay 1 in Education & Reference ➔ Homework Help
pencil : x
pen : y
12x+6y=120
2y=3x+5
3x=2y-5
x=(2y-5)/3
12*((2y-5)/3)+6y=120
14y=140
y=10 , x=5
y+x=15
2006-06-07 23:05:48 · answer #1 · answered by gizmo 2 · 1⤊ 0⤋
I don't know whether you really cannot solve this question or you're just lazy.
Pencil = x
Pen = y
12x + 6y = 120
2y = 3x + 5
12x + 3(2y) = 120
12x + 3(3x + 5) = 120
21x + 15 = 120
x = 5
y = 10
A pencil is $5; a pen is $10
2006-06-08 08:53:43 · answer #2 · answered by Dav 2 · 0⤊ 0⤋
12 pencils and 6 pens for $120. I'd go to another newsagent.
2006-06-08 06:00:39 · answer #3 · answered by Scozbo 5 · 0⤊ 0⤋
u have to figure it out ur self, put in ur best efforts n u surely will find the answer. if u start depending on others for such small things u can never achieve success in life
best of luck in solving the problem
2006-06-08 06:07:52 · answer #4 · answered by chris 3 · 0⤊ 0⤋
Don't let other people do ur homework.If this thing comes for a test,u wont have Yahoo answers then,will u.So,put in ur best (log off 1st).
2006-06-08 06:48:25 · answer #5 · answered by Zeta 6 · 0⤊ 0⤋
hey. ur making others finish ur maths homework arent u?
go figure. learn. =)
2006-06-08 05:59:04 · answer #6 · answered by vainybaby 3 · 0⤊ 0⤋
damn I finish school to long ago
2006-06-08 06:02:13 · answer #7 · answered by Anonymous · 0⤊ 0⤋