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Ulleksa [173]
3 years ago
8

Kiran is playing a video game. He earns 3 stars for each easy level he completes and 5 stars for each difficult level he complet

es. He completes more than 20 levels total and earns 80 or more stars
Mathematics
1 answer:
Marina86 [1]3 years ago
7 0

Answer:

10 easy levels and 10 difficult levels

Step-by-step explanation:

Given data

let the number of easy levels be x

and the number of difficult levels be y

so

x+y= 20----------1

and

3x+5y= 80------2

from 1

x=20-y

put this in 2

3(20-y)+5y= 80

60-3y+5y=80

2y=80-60

2y=20

y= 20/2

y= 10

put y= 10 in 1

x+10=20

x=20-10

x= 10

Hence Kiran played 10 easy levels and 10 difficult levels

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Write the set of in roster form if M is the set of integers that are greater that -1 and less than 4?
olchik [2.2K]
If I could understand what you meant my answer is: Set M consisting of 0,1,2 and 3 whose power set has 16 individual sets :)
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4 years ago
5x^2-2x=2<br>help plsmmm​
Yuki888 [10]

Answer:

Presumably you're solving for x here?  Without further information we'll assume that.

With that in mind, x is approximately equal to 0.86 and -0.46

Step-by-step explanation:

Let's start by putting it in the usual ax² + bx + c format.

5x^2- 2x = 2\\5x^2 - 2x - 2 = 0\\

let's solve it.  First we'll multiply both sides by five, making the first term a perfect square:

25x^2 - 10x - 10 = 0\\

Now we'll add 11 to both sides:

25x^2 - 10x + 1 = 11\\

Which makes the left side a perfect square:

(5x - 1)^2 = 11

And now we can solve for x:

(5x - 1)^2 = 11\\\\5x - 1 =  \sqrt{11} \\\\5x = 1 + \sqrt{11}\\\\x = \frac{1 + \sqrt{11}}{5}

Note that there's no apparent way of drawing the ± symbol when editing equations, so take that + sign as actually being ±.

That gives us two answers:

x = \frac{1 + \sqrt{11}}{5}\\\\x \approx \frac{1 + 3.32}5\\\\x \approx \frac{4.32}5\\\\x \approx 0.86             x = \frac{1 - \sqrt{11}}{5}\\\\x \approx \frac{1 - 3.32}5\\\\x \approx \frac{-2.32}5\\\\x \approx -0.46

7 0
3 years ago
The half-life of cesium-137 is 30 years. Suppose we have a
VMariaS [17]
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(c)
100 e^{- (\ln 2)t/30} = 1\ \implies\ -(\ln 2) t / 30 = \ln \frac{1}{100}\ \implies\ \\ \\&#10;t = -30 \frac{\ln 0.01}{\ln 2} \approx \text{199.3 years}
 
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3 years ago
Destiny has 10$ and Elijah has 5$. I give each person the same amount of money each week. This situation can be represented with
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Answer:

I do believe that the answer is 0 solutions.

Step-by-step explanation:

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x+5=x

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8 0
3 years ago
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Paul [167]
3 - 2a > 7
We need to solve for a

First, let's subtract 3 on both sides to have the variables on a side and the numbers on another side:
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Let's divide both sides by -2 to have a on side and its value on the other side:
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So 3 - 2a > 7 when a < -2 (answer c)

Hope this helps! :D

3 0
3 years ago
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