This is problem #9. I'm not sure how to solve #10, although the solution may be found in a similar way.
So we have the equations:
y - 4x = 2 --- equation 1
5y - 2x = 1 --- equation 2
(equation 2) * 2
10y - 4x = 2 --- equation 3
(equation 2) - (equation 3)
-9y = 0 so y= 0 and thus x = -1/2
Hope that helps!
43-2(11)=43-22=21
The answer is 21
9514 1404 393
Answer:
18.98 pounds
Step-by-step explanation:
Let 'e' represent the number of pounds of expensive candy Ellen should use. Then 27-e is the number of pounds of less expensive candy. Her total cost is ...
1.45(27 -e) +3.74e = 27(3.06)
(3.74 -1.45)e = 27(3.06 -1.45) . . . . subtract 1.45(27)
e = 27(3.06 -1.45)/(3.74 -1.45) = 27(1.61/2.29) ≈ 18.98
Ellen should use about 18.98 pounds of the expensive candy.
_____
<em>Additional comment</em>
We showed the solution this way because it is the generic solution to any mix problem. The fraction of the mix that is the highest-value contributor is the ratio of the difference between the mix value and the lowest contributor to the difference between contributors. Here, that fraction is ...
(3.06 -1.45)/(3.74 -1.45) = (1.61/2.29)