Question

if 10 pens and 15 pads of paper cost $26, and 5 of the same pens and 10 of the same pads cost $16, find the cost of a pen and a pad.

Answer 1

\[10x+15y=26\]
\[5x+10y=16\] is what you need to solve

Answer 2

multiply second equation by -2 to get
\[10x+15y=26\]
\[-10x-20y=-32\] add to get
\[-5y=-6\]
\[y=\frac{6}{5}=1.2\]

Answer 3

so pads cost $1.20

Answer 4

clear?

Answer 5

What about pen?

Answer 6

find x..

Answer 7

we substitute y = 1.2 into equation to solve for x

Answer 8

right

Answer 9

well if you know the price of the pad, you certainly know the price of the pen. ten pads cost $12 so 5 pens cost $4 so each pen is $.80

Answer 10

okay. just wanted to check my answer. i made the mistake of dividing -6 by something to get .83, but i get it now.

Answer 11

\[\checkmark\]

Answer 12

how to do that satellite?