Question

Solve the system by graphing.

Answer 1

Sue, you know this stuff :)

Answer 2

I feel like I do but when I start I can't finish :(

Answer 3

"I can do this, because I am smart enough..."

(repeat) :)

Answer 4

Ok, let's go...

Answer 5

lol

Answer 6

eq 1: -5x - y = -11

let's put it in y = mx + b format... that's a nice equation for a line, don't you think?

Answer 7

y = -5x +(-11)

Answer 8

nice start... :)

How about Eq 2? 2x - y = 10

Answer 9

y = 2x + 10

Answer 10

Oops... close... 2x - y = 10 --->>>> y = 2x - 10... do you see it?

So you have:

Eq 1: y = -5x + (-11) ----->>> y = -5x -11
and
Eq 2: y = 2x - 10

Answer 11

yep so now I add them both together?

Answer 12

Well, it says solve by graphing...

Otherwise, you could add them together and solve directly.

Do you know how to solve by graphing?

Answer 13

nooooo

Answer 14

Thoughts? Sounded like you knew how to solve it by algebra...

Can you plot both lines that you set up as Equations 1 and 2?

Answer 15

y = -5x -11
+
y = 2x - 10
---------------
y = -3x - 21

Answer 16

Two things... first, the problem asks you to graph it. You are right, you could try to solve it as "2 equations, 2 unknowns", but here, they really want you to plot the lines and find the intersection.

Second, though... supposing that you just wanted to solve by algebra to get an idea of the solution before you graphed it, you made an error when you added the two equations.

on the right side, all is well :)

on the left side, you added y and y and got.... y. Should be y + y = 2y on the left, right?

Answer 17

I was going to do that but I thought I would be wrong

Answer 18

so 2y = -3x - 21

Answer 19

By graphing it you have the find the points of intersection because that's what the solution is.

Do you know how to do that by using a graphing calculator?

Answer 20

http://www.wolframalpha.com/input/?i=plot%28-5x-y%3D-11%2C2x-y%3D10%29