Hey there!
<em>C = 0.25x + 40</em>
(a) For this part we solve for C when x = 240. Substitute 240 in for x.
C = 0.25(240) + 40
Multiply 240 by 0.25.
C = 60 + 40
Add.
C = 100
The cost is $100.
<u>Check</u>
100 = 0.25(240) + 40
100 = 60 + 40
100 = 100
(b) For this part we solve for x when C = 180. Substitute 180 for C.
180 = 0.25x + 40
Subtract 40 from each side.
140 = 0.25x
Divide each side by 0.25.
560 = x
This person drove 560 miles.
<u>Check</u>
180 = 0.25(560) + 40
180 = 140 + 40
180 = 180
(c) For this we must make an inequality with C = 150.
Since they want the cost to be <em>no more than</em> 150, we will use the ≥ symbol.
C ≥ 0.25x + 40
Substitute 150 for C. Solve for x.
150 ≥ 0.25x + 40
Subtract 40 from each side.
110 ≥ 0.25x
Divide each side by 0.25.
440 ≥ x
The max number of miles they can drive is 440.
<u>Check</u>
150 ≥ 0.25(440) + 40
150 ≥ 110 + 40
150 ≥ 150
Hope this helps!
<h3>
Answers:</h3>
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Explanation:
The given piecewise function is

At first piecewise functions may be strange confusing things, but they aren't so bad. I like to think of it like this: f(x) is a function that changes its identity based on what the input x is. We have three situations
- f(x) = -4x+3 when x < 3
- f(x) = -x^3 when

- f(x) = 3x^2+1 when x > 8
In a sense, we have three different functions but they are combined somehow.
If x is smaller than 3, then we go for the first definition. Or if x is between 3 and 8, then we go for the second definition. Or if x is larger than 8, then we go for the third definition.
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f(-5) means f(x) when x = -5. We see that -5 is smaller than 3, so x = -5 makes x < 3 true. We'll use the first definition
f(x) = -4x+3
f(-5) = -4(-5)+3
f(-5) = 20+3
f(-5) = 23
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Now the input is x = 12. This is larger than 8. In other words, x = 12 makes x > 8 true. We'll use the third definition
f(x) = 3x^2+1
f(12) = 3(12)^2+1
f(12) = 3(144)+1
f(12) = 432+1
f(12) = 433
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Side notes:
- We won't use the second definition since we don't have any x inputs between 3 and 8
- To say "less than or equal to" on a keyboard, you can write "<=" without quotes. For example,
is the same as x<=5
Answer:
216π in²
Step-by-step explanation:
Base area = π × r²
36 π = π × r²
r² = 36
r = 6
Volume = base area × height
432 π = 36 π × height
height = 12
Surface area:
2 × π × r × (r + h)
2π × 6 × (6 + 12)
216π
22.5/(x-6) + 22.5/(x+6) = 9
multiply by x-6
=> (x-6)22.5/(x-6) + (x-6)22.5/(x+6) = 9(x-6)
=> 22.5 + (x-6)22.5/(x+6) = 9(x-6)
multiply by x+6
=> (x+6)22.5 + (x+6)(x-6)22.5/(x+6) = 9(x-6)(x+6)
=> (x+6)22.5 + (x-6)22.5 = 9(x-6)(x+6)
distribute
=> 22.5x+6(22.5) + 22.5x - 6(22.5) = 9(x^2 - 36)
=> 45x = 9x^2 - 9(36)
=> 0 = 9x^2 - 45x - 9(36)
divide by 9
=> 0 = x^2 - 5x - 36
=> 0 = x^2 - 5x - 36
=> 0 = (x - 9)(x + 4)
x=9 and -4
Answer:
todays my birthday
Step-by-step explanation: