system of equations

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Psychguy98

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x/3 = y/5 and 3 + y = z

Which of the following equations , together with the two equations above, will form a system of three equations such that there is only one value of x that satisfies all three equations?

a.) z + y = 5
b.) y = z -3
c.) 5x = 3y
d.) z-y = 3
e.) x = 3/5y

Should i solve each equation and go through the ones it can't be?
 
Psychguy98 said:
Should i solve each equation

What do you mean by writing "solve each equation"?

Please show your work on this, so that we might understand what you're talking about.


and go through the ones it can't be?

If you already know "the ones it can't be", why would you want to "go through" them?

I do not understand this question, either.

Please show your work, so that we might understand what you're talking about.
Click to expand...

EG:

Here's the first system.

x/3 = y/5

3 + y = z

z + y = 5

The solution to this system is:

x = 3/5

y = 1

z = 4

What do you think about this?

 
Psychguy98 said:
x/3 = y/5 and 3 + y = z

Which of the following equations , together with the two equations above, will form a system of three equations such that there is only one value of x that satisfies all three equations?

a.) z + y = 5
b.) y = z -3
c.) 5x = 3y
d.) z-y = 3
e.) x = 3/5y

Should i solve each equation and go through the ones it can't be?
Click to expand...

I am not sure exactly what you mean by - "solve each equation".

The best way to solve this problem is to find out whether any of the five givenas answer is different (independent) from the any of the given in the problem.

for example c (5x -3y = 0) is same as the first equation given (x/3 = y/5). So c is NOT the answer because it is not independent equation.

And so on.....
 
Sorry, I mean it can't answer E because you can get x = 3/5y from x/3 = y/5. You can get answer D, z-y = 3 by solving 3 + y = z?
 
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