Question

A student government organization is selling Christmas trees as a fundraiser. On Friday, they sold 5 noble fir trees and 3 douglas fir trees for a total of $420. On Saturday, 12 noble fir trees and 9 douglas fir trees were sold for a total of $1,080. What is the cost per tree for each type

Answer 1

Do you know how you would set up the 2 equations?

Answer 2

no

Answer 3

Let's first set up x and y, our two unknown variables
x will be noble fir trees, and y will be douglas fir treees

yea?

Answer 4

ok

Answer 5

5 noble fir trees and 3 douglas fir trees for a total of $420
So 5 x's and 3 y's equal 420

Can you set up this first equation

Answer 6

5x+3y=420

Answer 7

Yep, and now we set up the second
12 noble fir trees and 9 douglas fir trees were sold for a total of $1,080
12 x's and 9 y's equal 1080

what's the equation?

Answer 8

12x+9y=1080

Answer 9

Yep, so now we have
5x+3y=420
12x+9y=1080

I think that it might be easier if we first simplify the 12x+9y=1080
Can you divide both sides by 3?

Answer 10

(12x+9y)/3 = 1080/3

Answer 11

4x+3y+360

Answer 12

=

Answer 13

5x+3y=420
4x+3y=360

Do you know how to do the elimination method for linear equations?

Answer 14

yes i was just confused thank you for helping me

Answer 15

so you got the answer?

Answer 16

almost

Answer 17

oh
well, after you're done, you can check it with me if you want lol

Answer 18

thank you and i will lol

Answer 19

kay
and yw~

Answer 20

the answer is y=140-5/3x and y=120-4/3x

Answer 21

huh?
You're trying to solve for x and y with the equations
5x+3y=420
4x+3y=360

You don't have to isolate the y?

I suggest using the elimination method to do this?

Answer 22

ok

Answer 23

5x+3y=420
- 4x+3y=360

Answer 24

yes

Answer 25

Like
5x+3y=420, minus 4x+3y=360

So for x, we do 5x-4x
For y, we do 3y-3y
and then equals
420-360

So, what is it

Answer 26

x=60?

Answer 27

Yep~
So noble fir trees cost 60 dollars each
Now, plug in this x value into one of the two equations and solve for y

Answer 28

y=40

Answer 29

Yep, we get the the noble fir trees are 60 each, and douglas fir trees are 40 each

Answer 30

thank you i understand now

Answer 31

yw~!