Question

Ok I just need to know how to set this problem up and then I can solve it. One canned juice drink is 15% orange juice; another is 5% orange juice. How many litres of each should be mixed together in order to get 10L that is 7 % orange juice. I have to use a system of equations to solve this. Does x+y =7 and then 15x + 5y = (10)(7) make sense? Somebody please help I am still stuck on this question I have to use a system of equations to answer this. The equations I am using are not giving me the right answer.

Answer 1

\[.15x+.05(10-x)=.07\times 10\]

Answer 2

x+y=10
5x+15y=70

Answer 3

you do not need a "system"

Answer 4

yes you do

Answer 5

no, you do not

Answer 6

elixated I tried that system and it gave me a negative answer and that can't be right

Answer 7

you can solve it without a system but to get the quanity x-10 you should start witha system

Answer 8

I give u equation early
percent ---------------- quantity
Juice I 15 ---------------- x liters
JuiceII 5 ---------------- 10 - x liters
Total 7.00% ---------------- 10

15x+5(10-x)=7*10

15x+50-5x=70
15x-5x=70-50
10x=20 /10
x=2 liters 15.00%
8liters 5.00%

Answer 9

i just solved it without one. put the amount of 15% juice as say X. then the amount of 5% juice is 10-x

Answer 10

You did something wrong. When you solve it you should get a positive answer. I did.

Answer 11

ok here we go

Answer 12

x + y = 10
0.15x + 0.05y = (10)(0.07)
0.05y = -0.15x + 0.7
Y = -3x + 0.7
X – 3x +0.7 = 10
-2x + 0.7 = 10
-2x = 9.3
I didn't finish solving because I knew the answer would be negative

Answer 13

\[.15x+.05(10-x)=.07\times 10\]
\[15x+5(10-x)=70\]
\[15x+50-5x=70\]
\[10x+50=70\]
\[10x=70-50=20\]
\[x=\frac{20}{10}=2\]

Answer 14

Ok thank you that helps a lot

Answer 15

so i get 2 liters of 15% juice and therefore 10-2=8 liters of 5% juice. lets check the answer and see if it is right

Answer 16

you guys cannot use decimals. instead, set up your equation as:
x+y=10
5x+15y=70

Answer 17

\[2\times .15+8\times .05=.3+.4=.7\] and .7 is 70% of 10 so that is the answer

Answer 18

15y = -5x + 70
y = -1/3x + 70

x -1/3x + 70 = 10
2/3x + 70 = 10
2/3x = -60

answer will still be negative

Answer 19

"you guys cannot use decimals"??? can we use fractions? how about variables?

Answer 20

where on earth did
\[15y=-5x+70\] and
\[y=-\frac{1}{3}x+70\] come from?

Answer 21

because
5x + 15y = 70
-5x -5x
15y = -5x + 70
/15 /15
forgot to divide 70 by 15
y = -1/3x + 4 2/3

Answer 22

or 14/3

Answer 23

but then it would be

X + -1/3x + 14/3 = 10
2/3x + 14/3 = 10
2/3x + 14/3 = 30/3
2/3x = 16/3
x = 48/6 = 8

so not negative sorry