1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
swat32
3 years ago
14

Mardi received an inheritance of $40,000. She invested part at 9% and the rest at 12%. Her total annual income from the investme

nts was $3900. Find the amount she invested at 9%
Mathematics
1 answer:
-BARSIC- [3]3 years ago
5 0

Answer:

She invested $30,000 at 9%

Step-by-step explanation:

Let the amount invested per percentage be $x and $y respectively

Total investment is 40,000

This means that;

x + y = 40,000 ••••••••••(i)

Now for her income;

9/100 * x = 9x/100

for the 12% = 12/100 * y = 12y/100

Now;

9x/100 + 12y/100 = 3,900

9x + 12y = 390000 •••••••••(ii)

we solve both simultaneously

From i, y = 40,000-x

Substitute this into ii

9x + 12(40,000-x) = 390,000

9x + 480,000-12x = 390,000

3x = 480,000-390,0000

3x = 90,000

x = 90,000/3

x = $30,000

You might be interested in
<img src="https://tex.z-dn.net/?f=81-%28y-1%29%28y%5E2%2B27%29%20%5Cgeq%200%20%5C%5C%5C%5C%2081-%28y%5E3%2B27y-y%5E2-27%29%20%5C
Zarrin [17]
<span>First thing you'll need to know is that the value for this equation is actually an approximation 'and' it is imaginary, so, one method is via brute force method.

You let f(y) equals to that equation, then, find the values for f(y) using values from y=-5 to 5, you just substitute the values in you'll get -393,-296,-225,... till when y=3 is f(y)=-9; y=4 is f(y)=48, so there is a change in </span><span>signs when 'y' went from y=3 to y=4, the answer is between 3 and 4, you can work out a little bit deeper using 3.1, 3.2... You get the point. The value is close to 3.1818...

The other method is using Newton's method, it is similar to this but with a twist because it involves differentiation, so </span>y_{n+1}=y_n-\frac{f(y)}{f'(y)}<span> where 'n' is the number you approximate, like n=0,1,2... etc. f(y) would the equation, and f'(y) is the derivative of f(y), now what you'll need to do is substitute the 'n' values into 'y' to find the approximation.</span>
7 0
3 years ago
An equation that involves a multiplication addition, contains a variable, and has a solution of 8.
yulyashka [42]
A variable is an unknown like x so 

first we start with 
x=8
then we subtract (because you must add to reverse subtraction)
x-2=8-2
x-2=6
then we divide ( because you must multiply to reverse division)
(x-2)/3=6/3
(x-2)/3=2

find x
7 0
3 years ago
of the pets in the pet show 5/6 are cats.4/5 of the calico cats what fraction of the pets are calico cats
Bond [772]
The answer is 0.664 because you have to divide 4/5 and 5/6
3 0
3 years ago
How many squares does it take to make a square?
hodyreva [135]

Answer:

aaalot I'm guessing I'm stu.pid

6 0
2 years ago
Read 2 more answers
Find the equation (in slope-intercept form) of the line passing through the points with the given coordinates.
IgorLugansk [536]

9514 1404 393

Answer:

  y = 2x -6

Step-by-step explanation:

The slope is given by the formula ...

  m = (y2 -y1)/(x2 -x1)

  m = (-4 -2)/(1 -4) = -6/-3 = 2

The y-intercept is given by ...

  b = y -mx

  b = 2 -2(4) = -6

The equation in slope-intercept form is ...

  y = mx +b . . . . . line with slope m and y-intercept b

  y = 2x -6

8 0
3 years ago
Other questions:
  • Which normal distribution has the greatest standard deviation?<br>A.<br>B.<br>C.<br>D.
    11·2 answers
  • 7t2 – 14t 4t2 – 9 how do u solve this
    10·1 answer
  • Does anyone happen to know how to solve this?​
    14·1 answer
  • What is the linear function equation represented by the graph?
    6·1 answer
  • Select the ordered pair that is a solution to the function. (A point on the line.)
    7·1 answer
  • What is the answer<br><br> 10 x 57
    8·2 answers
  • Please help :,)) an explained answer would be nice but if not that's ok :)
    7·2 answers
  • Lan Ventor designs a new board game and offers the design to Paddington Games p.l.c.
    6·1 answer
  • Sonji bought a combination lock that opens with a four-digit number created using the digits 0 through 9. The same digit cannot
    6·1 answer
  • The graph of the step function g(x) = –⌊x⌋ + 3 is shown.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!