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ipn [44]
2 years ago
12

My teacher makes us read the book to learn and the book doesnt show how to solve something like this

Mathematics
1 answer:
Gre4nikov [31]2 years ago
7 0

If the mean score is 55% and the s.d. is 15%, then a test score of at least

55% + 1.5 × 15% = 77.5%

falls in the A range.

The next cutoff score is 0.5 s.d. from the mean, which is

55% + 0.5 × 15% = 62.5%

so any test score between 62.5% and 77.5% is in the B range.

The next cutoff is

55% - 0.5 × 15% = 47.5%

so a score between 47.5% and 62.5% gets a C.

The lower limit of the next range is

55% - 1.5 × 15% = 32.5%

so 32.5% - 47.5% gets a D.

Anything lower than 32.5% is an F.

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16 POINTS. Find x and y intercepts and show work. <br><br> I’m looking for number six.
aliya0001 [1]
X^4-3x³+4x
x^4-3x³+3x+x
(x^4+x)-(3x³-3x)
x(x³+1)-3x(x²-1)
x(x+1)(x²-x+1)-3x(x+1)(x-1)
x(x+1)(x²-x+1-3x+3)
x(x+1)(x²-4x+4)
x(x+1)(x-2)(x-2)
so x intercepts are (0,0), (-1,0) and (2,0)
the y intercept is (0,0)

8 0
3 years ago
What must be added to both sides in 4x² + 24x + 8 = 32 in order to complete the square?
Sergeu [11.5K]

Answer:

16

Step-by-step explanation:

To solve a quadratic equation by using the completing the square method, the coefficient of the square term i.e x² must be one (1).

Therefore, we would have to first make the coefficient of x² to be equal to 1.

4x² + 24x + 8 = 32

We would simplify the equation;

4x² + 24x = 32 - 8

4x² + 24x = 24

Divide all through by 4;

x² + 8x = 24

The value to be added = (8/2)² = 4² = 16

x² + 8x + 16 = 8 + 16

x² + 4x + 4x + 16 = 24

x(x + 4) + 4(x + 4) = 24

(x + 4)² = 24

Taking the square root of both sides;

x + 4 = ± 4.9

x = -4 ± 4.9

x = -4 + 4.9 = 0.9

or

x = -4 - 4.9 = - 8.9

<em>Therefore, 16 must be added to solve the quadratic equation by completing the square method. </em>

6 0
3 years ago
A dart is thrown upward with an initial velocity of 66 ft/s at an angle of elevation of 54°. Consider the position of the dart a
givi [52]

Answer:

Answer to the question:

Step-by-step explanation:

α= 54º

V= 66 ft/s

g= 9.8 m/s²

Vx= V * cos(54º) = 38.8 ft/s

Vy= V * sin(54º) = 53.4 ft/s

<u>PARAMETRIC EQUATIONS:</u>

x(t)= Vx * t

y(t)= Vy * t - (g * t²)/2

4 0
3 years ago
What is PR?<br><br> A. 1 7/8 cm<br> B. 10 cm<br> C. 13 1/3 cm<br> D. 15 cm
Bess [88]

Answer:

you answer should be b

Step-by-step explanation:

I am not 100% sure

8 0
3 years ago
Read 2 more answers
Standard form of a point that goes through-2,4 and the slope is -1/7
lesantik [10]

<u>Answer:</u>

Standard form of a line passing through (-2, 4) and having slope of  -1/7 is x + 7y = 26

<u>Solution:</u>

Given that we need to determine standard form of a line that goes through (-2 , 4) and slope of the line is -1/7

Standard form of line passing through point ( a , b ) and having slope m is given by

(y – b) = m ( x – a)   --------(1)

In our case given point is ( -2 , 4 ) and slope is -1/7 that means

a = -2 , b = 4 , m = -(1/7)

On substituting given value of a , b and m is equation (1) we get

(y-4)=\left(-\frac{1}{7}\right)(x-(-2))

=>(y-4)=\left(-\frac{1}{7}\right)(x+2)

=> 7( y - 4 ) = -x – 2

=> 7y + x = -2 + 28

=> x + 7y = 26  

Hence standard form of a line passing through (-2,4) and having slope of –(1/7) is x + 7y = 26

8 0
3 years ago
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