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2 years ago

For what value of r is the parallelogram a rhombus

Mathematics

1 answer:

Gre4nikov [31]2 years ago

5 0

Answer:

Step-by-step explanation:

7r+18=r²

r²-7r-18=0

factorizing

r²+2r-9r-18=0

r(r+2)-9(r+2=0

(r-9)(r+2)=0

r-9=0

r=9

check

(r²)=(9*9)=81

7r+18=7(9) + 8=81

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If you are 600 m from a batter when you see him hit a ball, how long will you wait to hear the sound of the bat hitting the ball

Molodets [167]

Answer:

The speed of sound at 20°C is 343.42 m/s.

You have to wait 1.75 seconds to hear the sound of the bat hitting the ball

Step-by-step explanation:

Speed of Sound

The speed of sound is not constant with temperature. Generally speaking, the greater the temperature, the greater the speed of sound.

The approximate speed of sound in dry air at temperatures T near 0°C is calculated from:

$\displaystyle v_{\mathrm {s} }=(331.3+0.606\cdot T )~~~\mathrm {m/s}$

The air is at T=20°C, thus the speed of sound is:

$\displaystyle v_{\mathrm {s} }=(331.3+0.606\cdot 20 )~~~\mathrm {m/s}$

$v_{\mathrm {s} }=343.42\ m/s$

The speed of sound at 20°C is 343.42 m/s.

To calculate the time to hear the sound after the batter hits the ball, we use the formula of constant speed motion:

$\displaystyle v=\frac{d}{t}$

Where d is the distance and t is the time. Solving for t:

$\displaystyle t=\frac{d}{v}$

Substituting the values v=343.42 m/s and d=600 m:

$\displaystyle t=\frac{600}{343.42}$

t = 1.75 s

You have to wait 1.75 seconds to hear the sound of the bat hitting the ball

6 0

3 years ago

Find the Area. Simplify your answer.

Vaselesa [24]

Answer:

Area = $9x^2$ square units

Step-by-step explanation:

Key skills needed: Area of a parallelogram

1) This shape is a parallelogram, and the way to find the area of a parallelogram is:

$A = bh$

A = area

b = base (the side at the bottom

h = the height ( the length that runs from one side to another and makes a right angle)

2) The base (b) would be 3x. The height (h) would also be 3x

3) This means A = $3x(3x)$

3 times 3 is 9 --> and x times x is $x^2$

Therefore the area is --> $9x^2$

Hope you understood and have a nice day!! :D

5 0

2 years ago

A bus traveled 150 mlles in 3 hours. At what average rate did the bus travel?

dezoksy [38]

50 Miles at an average rate

8 0

2 years ago

Please solve!!!!!!!!!!!

vivado [14]

Answer:

A=8x-8

B=5x+25

A=B(BEING corresponding angles)

8x-8=5x+25

8x-5x=25+8

3x=33

x=33/3

x=11

now 8x-8= 8×11-8

= 88-8

=80

5x+25= 5×11+25

=55+25

= 80

A=B#

4 0

2 years ago

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Complete the equivalent equation for –7x – 60 = x2 + 10x.

saw5 [17]

Answer:

x= -5, -12

Step-by-step explanation:

4 0

2 years ago

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