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3 years ago

Pleaseeee pleaseee help mee with precal...One root of 2x2 + 8x + c = 0 is r1 = 1 + √5. Find r2.

Mathematics

2 answers:

igomit [66]3 years ago

6 0

If a root is a+√b then another is a-√b because of quadatic formula

r2=1-√5

Alenkinab [10]3 years ago

5 0

R2=1-√5 is the correct answer hope this helped

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PLEASE HELP ME!!! The sum of two numbers is 46. When 30 is subtracted from 5 times the smaller the result is 3 times the larger.

Ipatiy [6.2K]

Answer:

m = 21

n= 25

Step-by-step explanation:

the equations are:

n + m= 46

5m-30 = 3n

plz vote brainliest :)

8 0

3 years ago

The grade point averages (GPA) for 12 randomly selected college students are shown on the right. Complete parts (a) through (c)

Ilya [14]

Answer:

$\bar X =\frac{2.3+3.1+2.8+1.7+0.9+4+2.1+1.2+3.6+0.2+2.4+3.2}{12}=2.29$

$s=1.09$

Step-by-step explanation:

For this case we have the following data given:

2.3 3.1 2.8

1.7 0.9 4.0

2.1 1.2 3.6

0.2 2.4 3.2

Since the data are assumedn normally distributed we can find the standard deviation with the following formula:

$\sigma =\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n}}$

And we need to find the mean first with the following formula:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

And replacing we got:

$\bar X =\frac{2.3+3.1+2.8+1.7+0.9+4+2.1+1.2+3.6+0.2+2.4+3.2}{12}=2.29$

And then we can calculate the deviation and we got:

$s=1.09$

7 0

2 years ago

Read 2 more answers

Solve the system of equations by the addition method.<br> 1 - 3x = -5y - 8<br> 6x<br> 3y = -5

Advocard [28]

$-3x = -5y -8~~~....(i) \\\\6x -3y = -5 ~~......(ii)\\\\\text{Multiply equation (i) by 2 and do (i) + (ii):}\\\\2 \cdot (-3x) + 6x -3y = 2(-5y-8) + (-5)\\\\\implies -6x +6x -3y = -10y -16 -5 \\\\\implies -3y = -10y -21\\\\\implies -3y +10y =-21\\\\\implies 7y = -21 \\\\\implies y = -\dfrac{21} 7 = -3\\\\\text{Substitute}~y =-3~ \text{in equation (ii):} \\\\6x - 3(-3) = -5\\\\\implies 6x +9 = -5\\\\\implies 6x = -5 -9 = -14\\\\\implies x = -\dfrac{14}6 = - \dfrac{7}3\\$

$\text{Hence}~ (x,y) = \left(-\dfrac 73, -3 \right)$

3 0

2 years ago

Help me please I don’t understand

sashaice [31]

Answer:

She stopped to rest for 45 minutes.

Step-by-step explanation:

It's where the line is straight. What's the second question?

4 0

3 years ago

Read 2 more answers

I need help on 8 9 and 10

Lerok [7]

9. x + (y - 3 - 4x + 2( 3x - (-y - 1) + 2y) - 3x)

= x + (y - 3 - 4x + 2 (3x + y - 1) + 2y - 3x)
= x + (y - 3 - 4x + 6x + 2y - 2 + 2y - 3x)
= (x - 4x + 6x - 3x) + (y + 2y + 2y) - (3+2)
= 0 + 5y - 5
= 5y - 5 (or simplified as 5(y-1)

10. 6 + (-a -3(b + 6(a - b)+4a) - 2b)
= 6 + (-a - 3(b + 6a - 6b + 4a) -2b)
= 6 + (-a - 3b + 18a - 18b + 12a - 2b)
= 6 + (-a + 18a + 12a) + (-3b - 18b - 2b)
= 6 + 29a - 23b

Lmk if it's wrong, I'll try to edit it.

4 0

1 year ago