Posted by **JT** on Thursday, September 20, 2012 at 9:58am.

How do I solve the following problems?

My homework was to correct a puiz that I failed, but I do not know how to solve these problems..please help!

Solving systems of equations using elimination:

7.) 10x - 10y = 0

5x - 4y = 8

Answer (8,8)

I got the right answer because this one was multiple choice, but it was because I guessed...I need to know how to work it out.

8.) -8x - 8y = -8

-5x + 16y = 16

9.)I need this one worked out...I guessed the right answer (7, -7)

2x + 3yy = -7

-3x - 2y = -7

10.) -8x + 8y = -16

-3x + 7y = 10

11. 8x + 14y = 128

6x + 2y = 62

- Advanced Alegebra -
**Steve**, Thursday, September 20, 2012 at 12:05pm
#7:

if 10x-10y=0, then 10x=10y, or x=y

plug that into the other equation to get

5x-4x = 8

x=8, so y=8

the others are basically the same. you can substitute, or eliminate.

#8:

-8x - 8y = -8

-5x + 16y = 16

x+y=1, so y = 1-x

-5x + 16(1-x) = 16

-21x = 0

x=0, so y=1

elimination:

#10

-8x + 8y = -16

-3x + 7y = 10

multiply top by 3 and bottom by -8 to get

-24x + 24y = -48

24x - 56y = -80

add them up to get

-32y = -128

y = 4, so x = 6

Try the others and come back if you get stuck. Show us whatcha got, and we can straighten it out if necessary.

If you get an answer, be sure to plug the values back into both original equations to make sure it is right.

## Answer This Question

## Related Questions

- Math - Solve the following system of equations using both substitutio and ...
- algebra - i need help with these problems (either a solution or how to plug them...
- Algebra 2 - Solving systems of linear equations in three variables. Ok so i don'...
- Math - I am having problems understanding how to solve problems like the ...
- Algebra SOLVING LINEAR EQUATIONS AND INEQUALITIES - Please help Im am Grade 5 ...
- Algebra 2 - "My husband's age," remarked a lady the other day, "is represented ...
- Algebra - Solve the following systems of equations using the addition (...
- Algebra - Solve the following systems of equations using the addition (...
- Algebra - Solve the following systems of equations using the addition (...
- algebra - I have a few problems I need you to take a look at and tell me if I ...

More Related Questions