7⋅(−4)⋅(−6) a. −168 b. −3 c. 17 d. 168

I need help please.

skelet666 [1.2K]

Answer:

Step-by-step explanation:

(x²-6x-3)(7x²-4x+7)= ?

Multiply each term of 2nd bracket with the 1st bracket:

=7x²(x²-6x-3) -4x(x²-6x-3) +7(x²-6x-3)

=7x^4-42x^3-21x^2-4x^3+24x^2+12x+7x^2-42x-21

Now solve the like terms:

=7x^4-46x^3+10x^2-30x-21

Therefore the answer is (x²-6x-3)(7x²-4x+7)=7x^4-46x^3+10x^2-30x-21 ....

5 0

3 years ago

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

Can someone answer this please

GarryVolchara [31]

32 players = 16 matches ( 32/2)

16 players = 8 matches ( 16/2)

8 players = 4 matches (8/2)

4 players = 2 matches ( 4/2)

2 players = 1 match

16 + 8 +4 +2 +1 = 31 matches

4 0

3 years ago

Find the equation of the linear function 'g' going through (20,5) and (-5,-8). Use 'u' for your input variable.

frosja888 [35]

Answer:

See below

Step-by-step explanation:

Use the slope-intercept form, which will be in this case:

g(u) = mu + b, where m is the slope, b is the y- intercept

Find the slope:

$m=(y_2-y_1)/(x_2-x_1)$
$m=(-8-5)/(-5-20)=(-13)/(-25)=13/25$

Find the value of the y-intercept:

$5=1/25*20+b$
$b=5-4/5=21/5$

The equation is:

$g(u)=\frac{13}{25} u+\frac{21}{5}$

3 0

2 years ago

Rhonda has $315 in her saving account. She wants to save at least $585. Write and

Roman55 [17]

Answer:

0.53

Step-by-step explanation:

5 0

3 years ago