Question

How do you solve the following equation by using the graphing method?

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

Answer 1

i would change them into y=mx+b graph the lines

Answer 2

y = 3 - x/2
y = 4 - 2x/5

Answer 3

yup

Answer 4

yes thats right

Answer 5

First Convert both of these equations to y = mx + b format:
3x + 6y = 18 --> 6y = -3x + 18
y = -1/2x + 3

And...:
2x + 5y = 20 --> 5y = 2x + 20
y = 2/5x + 4

Now graph:
1) Y = -1/2x + 3
- Point on yintercept of 3..and then Go down 1 and right 2 (hence slope is -1/2) Keep going down one and right 2 until you create a long enough line..
Do the same with the second equation, and then when done graphing, they should intersect. The point or coordinates that they intersect on is your y and x value.

Answer 6

oh ok thank u :)

Answer 7

Katrina, your second equation is wrong

Answer 8

Anytime =)

Answer 9

you dont need to convert them into anything; the equation of a line is the equation of a line regardless of whatever form its in ...

Answer 10

Why does Katrina get three medals for getting it wrong?

Answer 11

Tough crowd

Answer 12

oh, it wasnt wrong :) just alot of extra work in my book

Answer 13

well, apart from the wrongness lol

Answer 14

if im gonna convert ill do this :)

3x + 6y = 18

x y
--- + --- = 1 ; (0,3) (6,0)
6 3


2x + 5y = 20


x y
--- + --- = 1 ; (0,4) (10,0)
10 4

Answer 15

3x + 6y = 18

x intercept=(6,0)
y intercept=(0,3 )

connect two points

Answer 16

She asked about "graphing" it

Answer 17

in order to graph, you gotta get at least 2 points per linear equation

Answer 18

That's the reason why I always put it in y = mx + b form when I'm solving. I always graph it to check my answer

Answer 19

She said how do you SOLVE BY graphing it..

Answer 20

do the same with other equation

Answer 21

Yeah, but she wanted to graph it on a calculator, using the "input" function....you know, using y = mx + b form

Answer 22

You would have had to be here earlier to understand