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3 years ago

Without computing, how do you know that the answer to 7-(-15) is posotive?

1 answer:

8 0

Hello, and thank you for posting your question here on brainly.

We have a trick in my school named "the cupid rule", where if you're subtracting a negative that's in parenthesis, we put a ♥ over the two negatives, and turn it into a positive, so now it's 7 + 15.

(it's 22)

Hope this helps! ☺♥

kaylie

2 years ago

this is not brainly lol

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Of the following numbers: 36, 56, 78, 98, 100, 1,000, 5,000, 10,000, 100,000, 500,000; what is the range.

Lubov Fominskaja [6]

Answer:

the is x 10

Step-by-step explanation:

6 0

2 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

2 years ago

The point (0, –4) is located . A coordinate plane.

Citrus2011 [14]

Answer:

On the x- axis

Step-by-step explanation:

6 0

2 years ago

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A baseball has a 48 cm diameter. What is the volume of the contents of the ball?

Andrew [12]

Answer:

201cm

Step-by-step explanation:

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2 years ago

Because of the rainy season, the depth in a pond increases 3% each week. Before the rainy season started, the pond was 10 feet d

Dafna11 [192]

It's not perfectly clear, but you seem to be saying that each week, the
pond becomes 3% deeper than it was THE PREVIOUS WEEK.

If I'm reading that correctly, then the pond is 10-ft deep when the rainy
season begins, and after 'x' weeks later, the depth is

   D = 10 (1.03)^x feet.

After 8 weeks, the depth is D = 10 (1.03)⁸ = 12.67 feet .

       rounded to the nearest foot, D = 13 ft.

7 0

3 years ago

Read 2 more answers