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3 years ago

Can someone help me with this?

Mathematics

1 answer:

Alex73 [517]3 years ago

5 0

Answer:

A. 6 hours

B. No students studied for 6 hours

C. 4 students

(I’m just using a educated guess for B)

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Choose the equation below that represents the line passing through the point (-3,-1) with a slope of 4.

Bingel [31]

Y = mx + b
slope(m) = 4
(-3,-1)...x = -3 and y = -1
now we sub...we r looking for b, the y int.
-1 = 4(-3) + b
-1 = -12 + b
-1 + 12 = b
11 = b

so ur equation is : y = 4x + 11

8 0

3 years ago

NASA launches a rocket at t = 0 seconds. Its height, in meters above sea-level, as a function of time is given by h ( t ) = − 4.

Oliga [24]

Answer:

$\displaystyle 1)48.2 \: \: \text{sec}$

$\rm \displaystyle 2)3021.6 \: m$

Step-by-step explanation:

<h3>Question-1:</h3>

so when flash down occurs the rocket will be in the ground in other words the elevation(height) from ground level will be 0 therefore,

to figure out the time of flash down we can set h(t) to 0 by doing so we obtain:

$\displaystyle - 4.9 {t}^{2} + 229t + 346 = 0$

to solve the equation can consider the quadratic formula given by

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

so let our a,b and c be -4.9,229 and 346 Thus substitute:

$\rm\displaystyle t = \frac{ - (229) \pm \sqrt{ {229}^{2} - 4.( - 4.9)(346)} }{2.( - 4.9)}$

remove parentheses:

$\rm\displaystyle t = \frac{ - 229 \pm \sqrt{ {229}^{2} - 4.( - 4.9)(346)} }{2.( - 4.9)}$

simplify square:

$\rm\displaystyle t = \frac{ - 229 \pm \sqrt{ 52441- 4( - 4.9)(346)} }{2.( - 4.9)}$

simplify multiplication:

$\rm\displaystyle t = \frac{ - 229 \pm \sqrt{ 52441- 6781.6} }{ - 9.8}$

simplify Substraction:

$\rm\displaystyle t = \frac{ - 229 \pm \sqrt{ 45659.4} }{ - 9.8}$

by simplifying we acquire:

$\displaystyle t = 48.2 \: \: \: \text{and} \quad - 1.5$

since time can't be negative

$\displaystyle t = 48.2$

hence,

at 48.2 seconds splashdown occurs

<h3>Question-2:</h3>

to figure out the maximum height we have to figure out the maximum Time first in that case the following formula can be considered

$\displaystyle x _{ \text{max}} = \frac{ - b}{2a}$

let a and b be -4.9 and 229 respectively thus substitute:

$\displaystyle t _{ \text{max}} = \frac{ - 229}{2( - 4.9)}$

simplify which yields:

$\displaystyle t _{ \text{max}} = 23.4$

now plug in the maximum t to the function:

$\rm \displaystyle h(23.4)- 4.9 {(23.4)}^{2} + 229(23.4)+ 346$

simplify:

$\rm \displaystyle h(23.4) = 3021.6$

hence,

about 3021.6 meters high above sea-level the rocket gets at its peak?

5 0

3 years ago

What is x? 4(x - 4) + 65 = -3x

svet-max [94.6K]

4(x - 4) + 65 = -3x
4(x) - 4(4) + 65 = -3x
4x - 16 + 65 = -3x
4x + 49 = -3x
- 4x - 4x
49 = -7x
-7 -7
-7 = x

8 0

3 years ago

On factorising 14pq + 35pqr. we get?

Anna71 [15]

Answer:

7pq( 2 + 5r)

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

What is the equation of the line that has a slope of 4 and passes through the point (-4,3)

Lisa [10]

Y=4x+19. To check your answer you can plug in the point (-4,3) into the equation to check your answer. Y=4x+19, 3=4(-4)+19, 3=3

4 0

3 years ago