Answer:
Option (C) and (D)
Step-by-step explanation:
Given piecewise function is,
f(x) = 2x, x < 1
5, x = 1
, x > 1
Option (A),
x = 5 means x > 1
So the function will be,
f(x) = ![x^{2}](https://tex.z-dn.net/?f=x%5E%7B2%7D)
f(5) = (5)²
= 25
Therefore, f(5) = 1 is not correct.
Option (B),
x = -2 means x < 1
f(x) = 2x will be applicable.
f(-2) = 2(-2) = -4
Therefore, f(-2) = 4 is not correct.
Option (C)
For x = 1,
f(1) = 5
Therefore, f(1) = 5 is the correct option.
Option (D)
x = 2 means x > 1 and the function defined will be,
f(x) = x²
f(2) = 2²
= 4
Therefore, f(2) = 4 will be the correct option.
Options (C) and (D) will be the answer.
The correct answer is the second choice.
Paolo made an error when he cross multiplied the proportion. He should have multiplied the 3 and the 8 and also the 12 and the x.
The second line should be:
12x = 24
Answer: False
Step-by-step explanation:
Set up the following equations:
![2x + 2y = 280](https://tex.z-dn.net/?f=2x%20%2B%202y%20%3D%20280)
![14x - 14y = 280](https://tex.z-dn.net/?f=14x%20-%2014y%20%3D%20280)
x represents car A's speed, and y represents car B's speed.
We'll use elimination to solve this system of equations. Multiply the first equation by 7:
![(2x + 2y = 280) * 7 = 14x + 14y = 1960](https://tex.z-dn.net/?f=%282x%20%2B%202y%20%3D%20280%29%20%2A%207%20%3D%2014x%20%2B%2014y%20%3D%201960)
![14x - 14y = 280](https://tex.z-dn.net/?f=14x%20-%2014y%20%3D%20280)
Combine both equations:
![28x = 2240](https://tex.z-dn.net/?f=28x%20%3D%202240)
Divide both sides by 28 to get x by itself:
![x = 80](https://tex.z-dn.net/?f=x%20%3D%2080)
The speed of car A is
80 mph.Since we now know the value of one of the variables, we can plug it into the first equation:
![2(80) + 2y = 280](https://tex.z-dn.net/?f=2%2880%29%20%2B%202y%20%3D%20280)
![160 + 2y = 280](https://tex.z-dn.net/?f=160%20%2B%202y%20%3D%20280)
Subtract 160 from both sides.
![2y = 120](https://tex.z-dn.net/?f=2y%20%3D%20120)
Divide both sides by 2 to get y by itself:
![y = 60](https://tex.z-dn.net/?f=y%20%3D%2060)
The speed of car B is
60 mph.