Question

Solve this system:
x+2y=5
2x+4y=2

Answer 1

You have several different methods of solution to choose from:
1. elimination by addition or subtraction
2. elim. by substitution
3. graphing

... and several more....
Which would YOU like to try first?

Answer 2

Erm,I've been trying elimination uvu

Answer 3

So, you've been trying elimination by substitution, or elimination by addition/subtraction? Which?

Answer 4

addition/subtraction

Answer 5

OK. Let's look at our system:

x+2y=5
2x+4y=2

I'd like for you to take the first equation and multiply every term in it by -2. Please type your result here.

Answer 6

he could just reduce the second equation

Answer 7

True, and I will suggest he heed your advice, later. Thanks.

Answer 8

my bad...I will not butt in again...sorry

Answer 9

-2x-4y=-20

Answer 10

wouldn't that be -10 instead of -20? What do you see here?

Answer 11

Sorry, I meant -10 but I'm trying to rush uAu

Answer 12

OK
x+2y=5
2x+4y=2

becomes -2x-4y = -10
2x+4y=2

Please combine all the like terms. In other words, combine -2x and 2x to obtain zero.

what about the y terms?
what about the constants on the right side of these equations?

Answer 13

That was my problem, they both are eliminated! But if you plug it in, then it's as if it has no solution

Answer 14

And -10 doesnt equal 2

Answer 15

That's exactly right. Since 0 on the left side cannot equal 2-10 on the right, this system of linear equations has no solution. that's it. End of story.

Answer 16

Note that we're not checking whether or not -10 equals 2; instead, we're combining those quantities; result is -8, right?

0 is not equal to -8, so our system has NO SOLUTION.

Answer 17

Thank youso much! I thought it would be no solution but I was doubting myself. uvu

Answer 18

I'm so glad we could work together and that this effort confirmed your initial solution. See you again on OpenStudy!