Pi = 3.14

The gas mileage for a certain vehicle can be approximated by m=−0.05x2+3.5x−49, where x is the speed of the vehicle in mph. Dete

Whitepunk [10]

Answer:

Step-by-step explanation:

Given the gas mileage for a certain vehicle modeled by the equation m=−0.05x²+3.5x−49 where x is the speed of the vehicle in mph. In order to determine the speed(s) at which the car gets 9 mpg, we will substitute the value of m = 9 into the modeled equation and calculate x as shown;

m = −0.05x²+3.5x−49

when m= 9

9 = −0.05x²+3.5x−49

−0.05x²+3.5x−49 = 9

0.05x²-3.5x+49 = -9

Multiplying through by 100

5x²+350x−4900 = 900

Dividing through by 5;

x²+70x−980 = 180

x²+70x−980 - 180 = 0

x²+70x−1160 = 0

Using the general formula to get x;

a = 1, b = 70, c = -1160

x = -70±√70²-4(1)(-1160)/2

x = -70±√4900+4640)/2

x = -70±(√4900+4640)/2

x = -70±√9540/2

x = -70±97.7/2

x = -70+97.7/2

x = 27.7/2

x = 13.85mph

x ≈ 14 mph

Hence, the speed(s) at which the car gets 9 mpg to the nearest mph is 14mph

4 0

3 years ago

2x+3y=1, -x+2y=-4 solve using substitution method

ollegr [7]

Step-by-step explanation:

1) 2x+3y-3y=1-3y. -x+2y= -4

2x/2=1-3y/2. -(1-3y/2)=-4

x=1-3y/2. -1+3y/2= -4

x=1-3(-2)/2 3y/2= -4+1

x=1+6/2 3y/2×2/3= -3×2/3

x=7/2 y= -2

S.s{ 7/3,-2}

2). -4x-6y+6y=7-6y. 4x+y= -2

-4x/-4=7-6y/-4. 4(-7-6y/4)+y= -2

x= -7-6y/4. -7-6y+y = -2

x= -7-6/4 -5y/5= 5/5

x=-13/4 y= 1

S.s { -13/4, 1 }

8 0

3 years ago

A bucket that weighs 4 lb and a rope of negligible weight are used to draw water from a well that is 60 ft deep. The bucket is f

jonny [76]

Answer:

2580 ft-lb

Step-by-step explanation:

Water leaks out of the bucket at a rate of $\frac{0.15 \mathrm{lb} / \mathrm{s}}{1.5 \mathrm{ft} / \mathrm{s}}=0.1 \mathrm{lb} / \mathrm{ft}$

Work done required to pull the bucket to the top of the well is given by integral

$W=\int_{a}^{b} F(x) dx$

Here, function $F(x)$ is the total weight of the bucket and water $x$ feet above the bottom of the well. That is,

$F(x)=4+(42-0.1 x)$

$=46-0.1x$

$a$ is the initial height and $b$ is the maximum height of well. That is,

$a=0 \text { and } b=60$

Find the work done as,

$W=\int_{a}^{b} F(x) d x$

$=\int_{0}^{60}(46-0.1 x) dx$

$&\left.=46x-0.05 x^{2}\right]_{0}^{60}$

$=(2760-180)-0[$

$=2580 \mathrm{ft}-\mathrm{lb}
$

Hence, the work done required to pull the bucket to the top of the well is $2580 \mathrm{ft}- \mathrm{lb}$

4 0

3 years ago

The first three terms of an arithmetic sequence are as follows.

Anna007 [38]

Answer:

The next two terms are 14 and 20.

Step-by-step explanation:

This is because the pattern is add 6, so you add 6 to 8 which equals 14, then 14 plus 6 equals 20.

5 0

3 years ago

How do I find the quotient 2/5 divide by 1/4

Artemon [7]

Answer:

A. $\frac{2}{5} \times 4$

Step-by-step explanation:

Given:

$\frac{2}{5} \div \frac{1}{4}$

To find the quotient, we would multiply the first fraction (⅖) by the reciprocal of the second fraction (reciprocal of ¼ = 4).

This, we would have:

$\frac{2}{5} \times 4$

$= \frac{8}{5}$

3 0

2 years ago