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3 years ago

Malorie can work 10 math problems in 3 minutes. At this rate, how many problems can she work in one hour?

1 answer:

4 0

D
If you multiply 3 by 10 and add a zero onto the ten in the question that is 100 in half an hour, all you need to do then is multiply that answer by two to get your answer.

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Can someone help me solve this?

Dovator [93]

Answer:

5 felt pads.

7 cards.

Step-by-step explanation:

Remark

The total number of items is 12
So let the felt sheets be x
Let the cards = y

Equations and Solution

x + y = 12

Now the price is 7.75 that she has to pay for the 12 items. She wants to come back with 0 dollars.

0.5x + 0.75y = 7.75 Multiply this equation by 2

x + 1.5y = 15.50 write the first equation underneath and subtract.

.5y = 3 Divide by 0.5

y = 3/0.5

y = 7

So she can get 7 cards.

x + y = 12

x + 7 = 12

x = 12 - 7

x = 5

So she can buy 5 felt pads.

8 0

3 years ago

Examine the quadratic equation 9x^2+12x +4= 0.

mestny [16]

Answer:

See answers and explanations

Step-by-step explanation:

A) Discriminant = b² - 4ac = (12)² - 4(9)(4) = 144 - 144 = 0

B) Since the discriminant is 0, this means the equation only has one root.

C) The root is real in this case since the discriminant is not negative. Otherwise, we would have two imaginary roots if it were (remember that complex roots come in pairs)

4 0

3 years ago

Sherlock Holmes discovers some hair fiber at a crime scene. He view the hairs through his magnifying glass from a distance of 6

snow_lady [41]

Answer:

24 cm.

Step-by-step explanation:

If you take 6 cm. and multiply it by 4(magnify it), you get 6 x 4, which is 24.

Hope this helps!

7 0

2 years ago

X2-3xy-5xy-7y2+4x2+8y2

Zepler [3.9K]

For this case we must simplify the following expression:

$x ^ 2-3xy-5xy-7y ^ 2 + 4x ^ 2 + 8y ^ 2$

We must add similar terms taking into account that:

Equal signs are added and the same sign is placed.

Different signs are subtracted and the major sign is placed.

$(x ^ 2 + 4x ^ 2) + (- 3xy-5xy) + (- 7y ^ 2 + 8y ^ 2) =\\5x ^ 2-8xy + y ^ 2$

Thus, the simplified expression is:

$5x ^ 2-8xy + y ^ 2$

Answer:

$5x ^ 2-8xy + y ^ 2$

4 0

3 years ago

Ron finds 9 books at a bookstore that he would like to buy, but he can afford only 5 of them. In how many ways can he make his s

pashok25 [27]

Answer:

15,120 for the first question. 1,680 if one of the books is a must

Step-by-step explanation:

When Ron chooses his first book, he has 9 options. After that, when he chooses his second book, he only has 8 choices because he already picked one of them. By his third choice, he only has 7 choices and so on.

We can make an equation to represent this,

9 x 8 x 7 x 6 x 5

Multiplying all of that out gets you 15,120.

The second problem is even easier. Since one of the books is already chosen for him, he starts off only having 8 options. Since he is only choosing four books this time, we are only multiplying four numbers.

8 x 7 x 6 x 5

Multiplying all of that out tells you there are 1,680 ways he can make his selection in the second scenario.

5 0

3 years ago