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

So you must set this up as a system of equations= noble fir trees= Douglas fir trees5n + 3d = $42012n + 9d = $1,080 To get a positive output you have to multiply the second equation by 3 to be able to be divisible to one another 36n + 18d = 3,240now divide the equation by 18 2n + d = 180-2n        -2nd = 180 - 2nNow put that equation in the first as d ^^^5n + 3(180 -2n) = 4205n + 540- 6n = 420       - 540         -540 1n = 120 n = 120 Now put n into the second equation( none changed one) to find d 12(120) + 9d = 3240 1440 + 9d = 3240 -1440        -14409d = 1800÷9    ÷9d= 200so the noble is $ 120 and the Douglas is $200

Answer 2

Friday it was 52.5 per types of tree 

Saturday it was 51.43 per types of tree
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