Question

Part 1: Explain, in complete sentences, how you would use the graphing method to solve the following system of equations. (3 points)

Part 2: Provide the solution to the system. (2 points)

Part 3: Explain what the solution represents on the graph. (1 point)

3x + 6y = 18
2x + 5y = 20

I'm so lost :(

Answer 1

plug in x = 0 to find y

3x + 6y = 18

3(0) + 6y = 18

0+6y = 18

6y = 18

y = 18/6

y = 3

so you have one point (0, 3) on the line 3x + 6y = 18

to find another point, plug in y = 0 and solve for x

Answer 2

So if x=6, what do I do next?

Answer 3

(6, 0) is another point on 3x + 6y = 18

Answer 4

you then plot the two points (0, 3) and (6,0)

then draw a straight line through them

Answer 5

So how does that get me to the solution?

Answer 6

you repeat the same steps to graph 2x + 5y = 20

Answer 7

where the two lines cross is where your solution point is

Answer 8

Ahh I see!

Answer 9

that's great

Answer 10

do you thinkyou could help me with the elimination method?

Answer 11

which variable do you want to eliminate

Answer 12

actually its a different problem, sorry my dog had to be let out

Answer 13

Part 1: Explain, in complete sentences, how you would use the elimination method to solve the following system of equations. (4 points)

Part 2: Provide the solution to the system. (2 points)

5x – 3y = 4
3x – 5y = –4

Answer 14

which variable do you want to eliminate

Answer 15

I have no idea, which would probably be the simplest?

Answer 16

either one is about the same amount of work, so just pick one

Answer 17

the first

Answer 18

ok if we just add 5x and 3x we get 8x

what we want is the two to add to 0x so the x terms get eliminated

Answer 19

how are we going to make the x terms add to 0x?

well we could multiply the 5x by 3 to get 15x
and we could multiply the 3x by -5 to get -15x

notice how 15x + (-15x) = 15x - 15x = 0x = 0

making sense so far?