Question

A Boy Scout troop is selling Christmas trees at a local tree lot in the morning they sold 11 Douglas fir trees and nine noble fir trees turning a total of $1006 in the afternoon they sold 14 Douglas fir trees and nine noble fir trees turning a total of $1111 how much do the Douglasfir trees cost

Answer 1

$35

Explanation:

Let x represent the price of Douglas fir trees and y represent the noble fir trees

11x + 9y= 1006........equation 1

14x + 9y= 1111.........equation 2

Multiply equation 1 by 14 and equation 2 by 11

154x + 126y= 14,084

-

154x + 99 y= 12,221

27y= 1863

Divide both sides by the coefficient of y which is 27

27y/27 = 1863/27

y= 69

Substitute 69 for y in equation 1

11x + 9y= 1006

11x + 9(69) = 1006

11x + 621= 1006

11x = 1006 -621

11x = 385

x = 385/11

x = 35

Hence the Douglas fir free costs $35