Doe anyone know some of these answers? Please help!! :confused:

x + y = 10
x - y = 4



4x - 3y = -2
-2x + 3y = 4


3x - 4y = -2
4x - 3y = -5



x + 4y = -5
3x + y = -4


2x - y = 10
x + 2y = -5

Ashliss07:

We won't do your homework for you, but here is a hint:

Each problem you've listed is a pair of statements with two unkowns (x and y). Take one of the statements and rephrase it so that either the x or the y is by itself on one side of the equation. You can then substitute that value into the other statement to determine one of the values. For example: the first problem includes the equation: x-y = 4. You can add y to both sides of the equal sign to get: x = 4+y. Do you see that? Then substitute this value for x into the first equation, so that x+y = 10 becomes (4+y) + y = 10. Now you can solve for y. Get it?

ebainesm the topic says to solve using elimination, not substitution.

Ashliss07, if you look at your first pair of equations, you see that you have +y in one and -y in the other. If you add the equations together, you get 2x = 14 because the y terms disappear, this gives you a value for x, which you can use to solve for y.

In the later questions, you might have to multiply up one of your equations in order to get a term that will disappear.

Please ask if you need further help.

x+y=8,000
x+y=600

x+y=8,000
x+y=600

The problem you posted here, deez5112 doesn't have any solutions. If, however, you meant:

x + y = 8 000
x - y = 600

Then, that's something different. Add the two equations:


x + y = 8000
x - y = 600
2x + 0 = 8600

Now that you have only one variable, you can solve the rest. :)