Molly has 10 pencils in her backpack. 4 of those pencils are red. What is the percent of pencils that are NOT red?

Eva8 [605]

The first step to solving this is converting these mixed numbers into improper fractions. You would do that by multiplying the denominator by the whole number and adding the numerator to that number; this number replaces the numerator. It would look something like this:

1 8/10 --> 18/10
2 2/5 --> 12/5

Now, to subtract the second fraction from the first one, the denominators of both fractions must be the same. We can make them the same by multiplying the second fraction by 2:

12/5 * 2/2 = 24/10

Now we can set up the equation as:

18/10 - 24/10 = -6/10 --> -3/5

The answer is negative 3/5.

I hope this helps.

5 0

3 years ago

You go shopping at a local department store with your friend and cousin. You buy one pair of jeans, four pairs of shorts, and tw

VashaNatasha [74]

Answer: Cost per pair of jeans = $ 20

Cost per pair of shorts = $12

Cost per shirt = $8

Step-by-step explanation:

Let x= cost per pair of jeans

y = Cost per pair of shorts

z= cost per shirt.

For you, total cost = x+4y+2z= 84

For your friend, total cost = 2x+y+3z=76

For cousin, total cost = x+2y+z= 52

Required system:

$x+4y+2z=84\ (i)\\ 2x+y+3z=76\ (ii)\\ x+2y+z=52\ (iii)$

from (i), $x=84-4y-2z$ (*)

put this in (ii) and (iii) we get

$2\left(84-4y-2z\right)+y+3z=76\\\Rightarrow\ -7y-z+168=76\ (iv)\\\\ 84-4y-2z+2y+z=52\\\Rightarrow\ -2y-z+84=52 \ (v)$

from (iv), $y=-\frac{z-92}{7}\ (vi)$

$\mathrm{Subsititute\:}y=-\frac{z-92}{7}\ \text{in}\ (v)$

$-2\left(-\frac{z-92}{7}\right)-z+84=52\\\\\Rightarrow\ -2\left(-\frac{z-92}{7}\right)-z=-32\\\\\Rightarrow\ -\frac{5z}{7}-\frac{184}{7}=-32\\\\\Rightarrow\ -5z-184=-224\\\\\Rightarrow\ -5z=-40\\\\\Rightarrow\ z=8$

$\mathrm{Subsititute\:}z=8\text{ in (vi)}$

$y=-\frac{8-92}{7}\\\\\Rightarrow \ y=12$

$\mathrm{Subsititute\:}z=8,\:y=12\text{ in (*)}$

$x=84-4\cdot \:12-2\cdot \:8\\\\\Rightarrow\ x= 20$

Hence, x= 20, y= 12 , z=8

So, Cost per pair of jeans = $ 20

Cost per pair of shorts = $12

Cost per shirt = $8

7 0

3 years ago

Which relation is a function?

Ksivusya [100]

B. To see if it’s a function, it has to pass the vertical line test. That means draw a vertical line (going up and down) through any point on the graph and it can only go through one point. If it goes through more than 1, it’s not a function. Like in graph A, if you draw a vertical line at x=-2, it will go through two points, same at x=2. For graph b, no matter where you move a vertical line, it only passes through one point at a time, so it passes the vertical line test.

8 0

2 years ago

Whats the average between these numbers:7.75,7.25,7.33,7.6?

satela [25.4K]

Step-by-step explanation:

Average between these no.s =

$\frac{7.75 + 7.25 + 7.33 + 7.6}{4}$