Question

solve the system by the elimination method

5x+3y=-7
7x-2y=13

Answer 1

Cali, do you want to try these on your own, or no?

Answer 2

or we can cheat. but we have to do something yes?

Answer 3

Satellite....lol

I'm sure she's taking a test...you don't have to stress her out any more than she already is....lol

Answer 4

well if i was taking an on line test i would cheat, and not rely on people here giving me goofy answers. i would cheat in such a way that i knew the answers were correct.

Answer 5

ok, teach me

Answer 6

Well, the simplest way to do this in my opinion would be to solve both equations for y. If you do that, you can then eliminate y by setting y = y and then solving for x. If you don't know how to solve equations for y, there really isn't much I can do for you.

Answer 7

okay here we go folks!

Answer 8

the simplest way it here
http://www.wolframalpha.com/input/?i=5x%2B3y%3D-7%2C+7x-2y%3D13

Answer 9

the next simplest way is to use matrices

Answer 10

Satellite, she said TEACH ME....I guess you just ignored that

Answer 11

i would never in a million years solve both for y, would you?

Answer 12

That's the way I've always done it

Answer 13

I was actually trying to teach, but the student is nowhere to be found!

Answer 14

Solving for y isn't that difficult. I can do it in one step

Answer 15

multiply equation 1 by 2 and equation 2 by 3 to get
\[10x+6y=-14\]
\[21x-6y=39\]

Answer 16

add them upo get
\[32x=25\]
\[x=\frac{25}{31}\]

Answer 17

that wasn't too bad was it?

Answer 18

Sometimes, you can't always solve it that way

Answer 19

really?

Answer 20

Medals for everyone! and bliss yea you can

Answer 21

if there is no solution you can't i suppose.

Answer 22

well true..

Answer 23

Okay...I don't like solving it that way...

Answer 24

the isolate y way would give u-
y=-5/3 x- 7/3
y=3.5x-6.5
I'd go with Satellite's way for this one, that doesn't look terribly fun to add and subtract