Answer:
x=-4, y=7
Step-by-step explanation:
According to the first equation, y = -4x - 9, so we can substitute y in the second equation for -4x - 9.
y = 3x + 19
-4x - 9 = 3x + 19
Add 9 to both sides
-4x = 3x + 28
Subtract 3x
-7x = 28
Divide by -7
x = -4
Plugging this into the equation, we have:
y = -4x - 9
y = -4(-4) - 9
y = 16 - 9
y = 7
Answer:
<em>The speed of sound at 20°C is 343.42 m/s.</em>
<em>You have to wait 1.75 seconds to hear the sound of the bat hitting the ball</em>
Step-by-step explanation:
<u>Speed of Sound</u>
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:
The air is at T=20°C, thus the speed of sound is:
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:
Where d is the distance and t is the time. Solving for t:
Substituting the values v=343.42 m/s and d=600 m:
t = 1.75 s
You have to wait 1.75 seconds to hear the sound of the bat hitting the ball
Answer:
-2
Step-by-step explanation:
Answer:
The correct option is B.
Step-by-step explanation:
According to AAS congruence rule, two triangles are congruent if two angles and a non included side are congruent to corresponding angles and side of another triangle.
We need two angles and a non included side, to use AAS postulate.
In option A, two sides and their inclined angle are congruent, therefore these triangles are congruent by SAS postulate and option A is incorrect.
In option B, two angles and a non included side are congruent, therefore these triangles are congruent by AAS postulate and option B is correct.
In option C, two angles and their included side are congruent, therefore these triangles are congruent by ASA postulate and option C is incorrect.
In option D, all sides are congruent, therefore these triangles are congruent by SSS postulate and option D is incorrect.
