F(x) = -9x^2 - 7x + 8
f(5) = -9(5^2) - 7(5) + 8
f(5) = -9(25) - 35 + 8
f(5) = - 225 - 35 + 8
f(50 = - 252 <==
Answer:
Barbara's speed in clear weather is 
and in the thunderstorm is 
.
Step-by-step explanation:
Let 
be the speed and 
be the time Barbara drives in clear weather, and let 
be the speed and 
be the time she drives in the thunderstorm.
Barbara drives 22 mph lower in the thunderstorm than in the clear weather; therefore,
(1). 
Also,
(2). 
(3). 
,
and
(4). 
From equations (2) and (3) we get:
putting these in equation (4) we get:
and substituting for from equation (1) we get:
This equation can be rewritten as
which has solutions
We take the first solution 
because it gives a positive value for 
.
Thus, Barbara's speed in clear weather is and in the thunderstorm is .
The formula for x in terms of other terms in the equation is; x = (cz-yw)/(y-c).
<h3>What is the formular for x in term of other terms in the equation?</h3>
According to the task content, it follows that the variable X is to be made the subject of the formula;
Hence, it follows that;
y ( x + w ) = c ( x + z )
yx +yw = cx +cz
x(y-c) = (cz-yw)
x = (cz-yw)/(y-c)
Remarks: The complete question requires that x be made the subject of the formula.
Read more on subject of formula;
brainly.com/question/11000305
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Answer:
Step-by-step explanation:
so Kennedy is right
