Ms. Kimura operates a soybean farm. She buys many supplies in bulk. Often the bulk products need to be custom mixed before Mrs. Huang can use them. To apply herbicide to a large field she must mix a solution of 67% herbicide with a solution of 46% herbicide to form 42 liters of a 55% solution. How much of the 67% solution must she use?
not sure if this is right, but if its is i dont know what to do next.
.67x + .46x= 42(.55)
2007-04-15 19:05:49 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
a.23L
b.18L
c.34L
d.35L
2007-04-15 19:21:02 · update #1
close!
.67x + .46(42-x) = 42(.55)
because there is only 42-x available for 46% if we use x for 67%
Solve this
67x +1932-46x=2310
21x= 378
x = 378/21 = 18
18 liters
:)
good work!
2007-04-15 19:10:42 · answer #1 · answered by Anonymous · 0⤊ 0⤋
You know that when you are done there will be 42 liters.
So one quantity will be an amount called x and the other will be 42-x.
So, .67x +.46(42-x) = 42 x .55
.21 x = 3.78
x = 18 liters of 67% solution
2007-04-15 19:16:48 · answer #2 · answered by ignoramus 7 · 0⤊ 0⤋
.67 Y , not X
and then
X + Y = 42
Solve for X in terms of Y - substitute in the Equation for X - gives you numbers and Y - solve for Y
plug back into X + Y = 42 to solve for X
2007-04-15 19:11:05 · answer #3 · answered by hornprof4Now 1 · 0⤊ 0⤋
(1) .67x + .46y = .55(42)
(2) x + y = 42 --> x = 42 - y
[substitute]
.67(42 - y) + .46y = .55(42)
28.14 - .67y + .46y = 23.1
.21y = 5.04
y = 24
x = 42 - (24)
x = 18
2007-04-15 20:18:09 · answer #4 · answered by Wallace T 2 · 0⤊ 0⤋
The equation should be
0.67x+0.46(42-x)=0.55*42
=> 0.67x+19.32-0.46x=23.1
=>0.21x=23.1-19.32=3.78
=> x=3.78/0.21=18
Therefore 18 litre of 67% solution should be used
2007-04-15 20:44:48 · answer #5 · answered by alpha 7 · 0⤊ 0⤋