help please

Let x be the original cost of one computer and y be the original cost of one printer.

So, the first equation is

3x + 1y = 1800

And when the price of a computer fell by  $500 we have....

2(x-500) + 2y = 1300     → 2x - 1000 + 2y = 1300→ 2x + 2y = 2300

So we have 2 equations

3x + 1y = 1800

2x + 2y = 2300

Multiplying the first equation by -2 on both sides, we have

-6x - 2y = -3600

2x + 2y =   2300

And adding them together, we have

-4x = -1300

Then the original cost of the computer was $325

And Melody's answer is correct !!! [This problem probably needs some "tweaking" so that the answer is  a "real-life" quantity...!!!]

for 1800$ you can buy 3 computers and 1 printer. if the price of a computer will go down by 500$, then for 1300$ you can buy 2 computers and 2 printers. what is the cost of a computer?

3C+1P=1800  (eqn 1a)  $$\rightarrow$$   P=1800-3C   (eqn 1b)

2(C-500)+2P=1300  (eqn 2a)

2C-1000+2P=1300   (eqn 2b)

2C+2P = 2300    (eqn 2c)

C+P=1150  (eqn 2d)

sub P=1800-3C into equation (eqn 2d)

C+1800-3C=1150

-2C=-650

C=$325

The original cost of the computer is $325

This doesn look right because it means that the price fell ot a negative number which is pretty silly.

But I will keep thinking about it anyway.

Check

1P=1800-3*625 = $825

3c+1P=3*325+825=$1800 correct

If the price of the computers fell by 500 then they fell to 325-500=-$175

Now 2 computers and 2 printers cost -175*2+2*825 = $1300  correct

Okay, the answer is correct.  The only way this works is if the computers have become so obsolete that the company will PAY $175 to have them taken away.