Answer:
Step-by-step explanation:
Picture
Answer:
Option B is correct
Step-by-step explanation:
Given:
f(x) = -20x^2 +14x +12 and
g(x) = 5x - 6
We need to find f/g and state its domain.
f/g = -20x^2 +14x +12/5x - 6
Taking -2 common from numerator:
f/g = -2(10x^2 - 7x - 6) / 5x -6
Factorize 10x^2 - 7x - 6= 10x^2 - 12x +5x -6
Putting in the above equation
f/g = -2(10x^2 - 12x +5x -6)/ 5x -6
f/g = -2(2x(5x-6) + 1 (5x-6)) / 5x-6
f/g = -2 ( (2x+1)(5x-6))/5x-6
cancelling 5x-6 from numerator and denominator
f/g = -2(2x+1)
f/g = -4x -2
The domain of the function is set of all values for which the function is defined and real.
So, our function g(x) = 5x -6 and domain will be all real numbers except x = 6/5 as denominator will be zero if x=5/6 and the function will be undefined.
So, Option B is correct.
<h3>Answers:</h3>
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Explanation:
x = number of seconds that elapse
y = altitude (aka height) of the plane
The equation for plane A is
y = 20.25x+2652
because it starts off at 2652 ft in the air, and then adds on 20.25 feet per second which is what the 20.25x describes
The equation for plane B is
y = 75.5x
The y intercept is zero because plane B starts on the ground, aka height 0.
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The system of equations is

If we want to know when they'll reach the same height (y), then we can set the two right hand sides equal to each other and solve for x.
75.5x = 20.25x+2652
75.5x-20.25x = 2652
55.25x = 2652
x = (2652)/(55.25)
x = 48
The two planes reach the same altitude at exactly <u>48 seconds</u>
That altitude is <u>3624 feet</u> because
- y = 20.25*x + 2652 = 20.25*48+2652 = 3624
- y = 75.5*x = 75.5*48 = 3624
Notice I plugged x = 48 into each equation and I got the same y value of y = 3624. This helps confirm the answers.