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4 years ago

Use the functions f(x) = 4x − 5 and g(x) = 3x + 9 to complete the function operations listed below.

1 answer:

5 0

Hello :
f(x) = 4x − 5 and g(x) = 3x + 9
(f + g)(x) = f(x) +g(x) = (4x-5) +(3x+9)
(f + g)(x) =7x +4
(f ⋅ g)(x) = f(x) × g(x) = (4x-5)(3x+9) = 12x² +36x -15x-45
(f ⋅ g)(x) = 12x² +21x -45
f[g(x)] = f(3x+9) = 4(3x+9) -5
f[g(x)] = 12x +31

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Al lives 30 mi. from Ann. At the same time, they start biking toward each other on the same road. Al’s constant rate is 12 mph.

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3 years ago

The archway of the main entrance of a university is modeled by the quadratic equation

Scilla [17]

Answer:

B. (1,5) and (5.25, 3.94)

Step-by-step explanation:

The answer is where the 2 equations intersect.

We need to solve the following system of equations:

y = -x^2 + 6x

4y = 21 - x

From the second equation:

x = 21 - 4y

Plug this into the first equation:

y = -(21 - 4y)^2 + 6(21 - 4y)

y = -(441 - 168y + 16y^2)+ 126 - 24y

y = -441 + 168y - 16y^2 + 126 - 24y

16y^2 + y - 168y + 24y + 441 - 126 = 0

16y^2 - 143y + 315 = 0

y = [-(-143) +/- sqrt ((-143)^2 - 4 * 16 * 315)]/ (2*16)

y = 5, 3.938

When y = 5:

x = 21 - 4(5) = 1

When y = 3.938

x = 21 - 4(3.938) = 5.25.

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3 years ago

in a survey, 27% of people chose salads over a meat dish. In all, 81 people chose salads. How many people were in the survey?

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Number of people that chose salad = 81
Percentage of people that chose salad over meat dish = 27%
Let us assume the number of people on the survey = x
Then
27% * x = 81
(27/100) * x = 81
27x = 81 * 100
27x = 8100
x = 8100/27
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So a total of 300 people participated in the survey.I hope the procedure is clear enough for you to understand. Based on this method you can always solve similar types of problems without requiring any kind of help from outside.

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3 years ago

Read 2 more answers

Please answer question three and four if you can :) Show full working out ty;)

nikklg [1K]

Step-by-step explanation:

Let D be the mid point of side BC, [B(2, - 1), C(5, 2)].

Therefore, by mid-point formula:

$D = ( \frac{2 + 5}{2}, \: \: \frac{ - 1 + 2}{2} ) = ( \frac{7}{2}, \: \: \frac{ 1}{2} ) \\ \therefore D= (3.5, \: \: 0.5) \\ \& \: A=(-1,\:\:4)...(given) \\\\ now \: by \: distance \: formula \\ \\ Length \: of \: segment \: AD \\ = \sqrt{( - 1 - 3.5)^{2} + {(4 - 0.5)}^{2} } \\ = \sqrt{(4.5)^{2} + {(3.5)}^{2} } \\ = \sqrt{20.25 + 12.25 } \\ = \sqrt{32.5} \\ \red{ \boxed{\therefore Length \: of \: segment \: AD = 5.7 \: units}}$

4 (a)

Equation of line AB[A(2, 1), B(-2, - 11)] in two point form is given as:

$\frac{y-y_1}{y_1-y_2} =\frac{x-x_1}{x_1 - x_2} \\\\\therefore \frac{y-1}{1-(-11)} =\frac{x-2}{2 - (-2) } \\\\\therefore \frac{y-1}{1+11} =\frac{x-2}{2 +2} \\\\\therefore \frac{y-1}{12} =\frac{x-2}{4} \\\\\therefore \frac{y-1}{3} =\frac{x-2}{1} \\\\\therefore y-1= 3(x - 2)\\\\\therefore y= 3x - 6+1\\\\\therefore y= 3x - 5\\\\ \huge \purple {\boxed {\therefore 3x - y-5=0}} \\$

is the equation of line AB.

Now we have to check whether C(4, 7) lie on line AB or not.

Let us substitute x = 4 & y = 7 on the Left hand side of equation of line AB and if it gives us 0, then C lies on the line.

$LHS = 3x - y-5\\=3\times 4-7-5\\= 12-12\\=0\\= RHS$

Hence, point C (4, 7) lie on the straight line AB.

4(b)

Like we did in 4(a), first find the equation of line AB and then substitute the coordinates of point C in equation and if they satisfy the equation, then all the three points lie on the straight line.

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4 years ago

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Percent is parts out of 100 so
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3 years ago

Read 2 more answers