ann,david, john are are at a coffee shop. ann orders four coffees, one juice and two donuts and pays$10.90. john orders one coffe and three donuts and pays $5.35.david orders three coffees one juice and four donuts and pays $11.80. find the price of coffee donuts and juice at this shop.
A. set up a linear system for the prices of the coffee juice and donuts
B. use cramers rule to solve the system remember to show all work

Question

ann,david, john are are at a coffee shop. ann orders four coffees, one juice and two donuts and pays$10.90. john orders one coffe and three donuts and pays $5.35.david orders  three coffees one juice and four donuts and pays $11.80. find the price of coffee donuts and juice at this shop.
A. set up a linear system for the prices of the coffee juice and donuts
B. use cramers rule to solve the system remember to show all work

anonymous · Answer

Let coffee = x, juice = y, donuts= z
Ann : 4x+y+2z=10.90
John : x+3z=5.35
David : 3x +y +4z = 11.80

anonymous · Answer

okay

anonymous · Answer

Then find D, Dx, Dy and Dz to solve for x,y,z

anonymous · Answer

i dont know how to solve for those

anonymous · Answer

$$\left(\begin{matrix}10.9 \ 5.35\ 11.8\end{matrix}\right)=\left(\begin{matrix}x \ y\z \end{matrix}\right)\left[\begin{matrix}4 & 1 &3 \ 1 & 3 & 1\ 2&0&4\end{matrix}\right]$$

anonymous · Answer

sorry it should be vertically 1st column 4,1,3 2nd column 1,31 and 3rd column 2,0,4

anonymous · Answer

http://www.purplemath.com/modules/cramers.htm