Question

An investor invested a total of $1300 in two mutual funds. One fund earned a 7% profit value while the other earned 4% profit. If the investor's profit was $85, how much was in each mutual fund? The amount invested in the fund that earned 7% was __________. The amount invested in the fund that earned 4% was ________>

Answer 1

please help i dont understand what to do

Answer 2

525 and 775 i got for answers

Answer 3

Those are not the answers.
I'm working on equations to try and help you.

Answer 4

ok ty

Answer 5

First equation is pretty simple
x - amount invested in 7% account
y - amount invested in 4% account

x + y = 1300

Answer 6

a+b=1300
.07a+.04b=85

Answer 7

Gee Amy that is impressive!!
Here's what I came up with
x = Amount invested in 7% interest account
y = Amount invested in 4% interest account

A) x + y = $1300
B) .07x + .04y = $85
Multiply equation B by -25 yields
-1.75x -1y = -2,125

Adding this equation to equation B yields
-.75x = -825
x = 1,100

Answer 8

1,100 is 7% profit and 825 is 4% profit

Answer 9

that does not add up

Answer 10

No the 825 is only part of that equation.
I did not post the y value.
if x + y = 1300 and x = 1100 what does y equal?

Answer 11

unless 200 goes for 4% and 1100 goes for 7% i hate math and my next class is the second part to this math and have not done this is 13 years

Answer 12

1100 * .07 = $77
200 * .04 = $8

77 + 8 = $85 :-)

Answer 13

so 77 is 7% 8 is 4 %

Answer 14

Yes

Answer 15

There's one thing you should know and that's how to solve for 2 equations
You did very well in coming up with one equation but I think you need help in solving those.

Answer 16

yeah its been a while it took me over three days and 6 hours to do one over and over again

Answer 17

Here is part of y solution:

A) x + y = $1300
B) .07x + .04y = $85
Multiply equation B by -25 yields
-1.75x -1y = -2,125

Do you know why I multiplied equation B by -25?

Answer 18

you have to multiply both sides to get the equation

Answer 19

Use elimination method

Answer 20

Yes, you always have to do the same thing to both sides of the equation.
Yes, I was using the elimination method.
You do remember huh?

Answer 21

it just getting it in the right order

Answer 22

Yes, I was messing up a lot on this one. Adding -1.75x to 1 - that sort of thing.

Answer 23

yeah i have another one

Answer 24

okay

Answer 25

an investor invested a total of $2800 in two mutual funds. One fund earned a 6% profit value while the other earned 2% profit. If the investor's profit was $120, how much was in each mutual fund? The amount invested in the fund that earned 6% was----. The amount invested in the fund that earned--- 2% was

Answer 26

yay more i hate these

Answer 27

but how do you know how to eliminate it with what

Answer 28

A) x = y = $2,800
B) .06x + .02y = $120

Answer 29

x+y=2800
.06+.02y=120

Answer 30

now elimnation part i get wrong all the time

Answer 31

would it be 12 or 8

Answer 32

Okay, we have to eliminate an x or a y from the equations when they are added together.
(What do you mean by 12 or 8?)

Answer 33

i added them sorry

Answer 34

Before you add them you have to determine which variable is to be eliminated.
So let's suppose BEFORE we add equation A & B - what variable do we eliminate?

Answer 35

x i think

Answer 36

Either can be eliminated but I think it is easier to eliminate y.
To eliminate 'y' we multiply equation B times -50
(If we wanted to elimnate 'x' we'd have to multiply by equation B by -16.6666666667
- not very neat is it?)

Answer 37

nope

Answer 38

And if you are wondering where the -50 comes from, it is the amount needed to produce a minus y in Equation B

Answer 39

ok

Answer 40

300 and 100 i got

Answer 41

.06x + .02y = $120
So, multiplying Equation B by -50 produces
-3x -y = -6,000

Answer 42

im confused now

Answer 43

the other one the answer was 1100 and 200

Answer 44

Yess 1100 and 200 were the previous answers.

Answer 45

Okay - this a place where you should NOT get confused.
We just multiplied equation B by -50 to get
-3x -y = -6,000
Now what do we do next?

Answer 46

Divide

Answer 47

No - think about it. In order to solve for 2 unknowns we need 2 equations.

Answer 48

A) x + y = $2800
B) .06x + .02y = $120
Multiply equation B by -50 yields
-3x -y = -6,000

Answer 49

That's right so now that we have that "new" equation B what do we do with it?

Answer 50

Use elimination method

Answer 51

Yes, and how do we eliminate a variable?

Answer 52

We multiplied Equation B times -50. Do you remember why?

Answer 53

to eliminate b

Answer 54

or to eliminate y (to use my nomenclature)

Answer 55

ok so now we eliminate x

Answer 56

well we have to eliminate y - you rememer what to do?

Answer 57

Adding this equation to equation B yields
-.50x = 6000

Answer 58

Actually we have to add the modified equation B to equation A
x = y = $2,800
-3x -y = -6,000

Answer 59

-2x-y=3200 is what i got unless i am doing it wrong

Answer 60

Yes, you shouldn't have any y value (and the 3200 should be negative). So, it should be
-2x = -3200

Answer 61

-2x=-3200

Answer 62

and so x = 1600

Answer 63

1200 is y

Answer 64

yes that's right

Answer 65

6% is 1600 and 2% would be 1200

Answer 66

yes

Answer 67

thank you I am not gonna do this assignment again i got the passing grade thank you for all your help and time

Answer 68

okay - you know what would help? Learning to solve for 2 unknowns with an easy example.

Answer 69

For example, try solving this:
3X + 2Y = 20
X + Y = 9