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2 years ago

8

There are five envelopes on a table. Four of the envelopes are marked 8, 2, 4 and 1. You are told that the mean of the numbers o

n the envelopes is 4. What is the number on the fifth envelope?

1 answer:

Lostsunrise [7]2 years ago

3 0

Answer: 16

Step-by-step explanation:

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30 girls tried out for lacrosse team and 12 were selected and 40 boys tried out 16 were selecyed are the ratio of the number of

Ivan

Yes it is. When you simplify the girls ratio( 12:30 by 6)you'll get 2:5. When you simplify the boys ratio( 16:40 by 8)you'll get 2:5. So it is the same ratio.

4 0

3 years ago

What are some equivalent fractions for the problem :<br> 9/2 ?<br><br> Thank you for your time :)

Varvara68 [4.7K]

First, if you convert the improper fraction 9/2 to a mixed number, it will be equal to 9/2.

9/2 = 4 1/2

And if you multiply the top and bottom of a fraction with an integer number, you will have a fraction that is equal to fraction you began with.

I'll use 5 for this example.

9/2 * 5/5 = 45/10

5 0

3 years ago

Which are the solutions of x2 = 19x + 1?

Finger [1]

Answer:

$(\frac{19-\sqrt{365}} {2},\frac{19+\sqrt{365}} {2})$

Step-by-step explanation:

we have

$x^2=19x+1$

we know that

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b\pm\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$-x^{2}-19x-1=0$

so

$a=1\\b=-19\\c=-1$

substitute in the formula

$x=\frac{-(-19)\pm\sqrt{-19^{2}-4(1)(-1)}} {2(1)}$

$x=\frac{19\pm\sqrt{365}} {2}$

$x=\frac{19+\sqrt{365}} {2}$

$x=\frac{19-\sqrt{365}} {2}$

$(\frac{19-\sqrt{365}} {2},\frac{19+\sqrt{365}} {2})$

therefore

StartFraction 19 minus StartRoot 365 EndRoot Over 2 EndFraction comma StartFraction 19 + StartRoot 365 EndRoot Over 2 EndFraction

6 0

3 years ago

Read 2 more answers

Solve the inequalities<br><br> -7d + 8 > 29

Arisa [49]

-7d > 21
d < -3

Remember the sign flips when you multiply or divide by a negative number.

3 0

3 years ago

Determine if they following is systems of equations?<br> y = 3x + 2<br> y = 7x -10

sergij07 [2.7K]

Answer:

Yes it is.

Step-by-step explanation:

7 0

3 years ago