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3 years ago

The relationship between the number of hours a plumber works and the total work fee

Mathematics

2 answers:

crimeas [40]3 years ago

7 0

Answer:

The answer is B,C, And D

Step-by-step explanation:

I just saw it on Khan and got it right.

Lynna [10]3 years ago

5 0

Answer:

ANSWERS ARE B, C, AND D.

Step-by-step explanation:

I found the unit rate of 350 and 5, because we can use a calculator (as stated on top) I just punched in 350 divided by 5 and got 70. Now i know this may not sound that "professional", but nothing needs to always be professional as long as its efficient and most importantly gets you the right answer. I then took the time to multiply each number, (the ones on the left : 3, 3.5, 6, 7.25, and 8) by 70. If the answer you got on the calculator match up to the number on the right, (240, 420, 507.50, and 490) its correct, if it doesn't match up, you can tell that its most likely not the answer. You should end up with three answers that all end up having the unit rate of 70. Hope this helps anyone who needed it.

ANSWERS ARE B, C, AND D.

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Evaluate g(n-7) if g(x) =x^2-5 / 3x

aleksandrvk [35]

Answer:

$g(n-7)=\frac{n^2-14n+44}{3n-21}$

Step-by-step explanation:

The given function is

$g(x)=\frac{x^2-5}{3x}$

To find g(n-7), we substitute x=n-7 to obtain;

$g(n-7)=\frac{(n-7)^2-5}{3(n-7)}$

Expand the parenthesis to obtain;

$g(n-7)=\frac{n^2-14n+49-5}{3n-21}$

Simplify:

$g(n-7)=\frac{n^2-14n+44}{3n-21}$

7 0

3 years ago

Perfect Linear relationship between two or more independent variables is a violation of .... a. MLR.1 - Linearity in parameters

nexus9112 [7]

Answer:

b. MLR.3 - No perfect collinearity assumption

Step-by-step explanation:

There is an assumption that nothing in the error term should correlate with the explanatory variable (x) of interest and outcome variable of (y). It does not allow any linear relation between two or more variables. If there is a relation between the variable it the the violation of this assumption.

4 0

3 years ago

A rancher wishes to build a fence to enclose a 2250 square yard rectangular field. Along one side the fence is to be made of hea

Bess [88]

Answer:

The least cost of fencing for the rancher is $1200

Step-by-step explanation:

Let x be the width and y the length of the rectangular field.

Let C the total cost of the rectangular field.

The side made of heavy duty material of length of x costs 16 dollars a yard. The three sides not made of heavy duty material cost $4 per yard, their side lengths are x, y, y. Thus

$C=4x+4y+4y+16x\\C=20x+8y$

We know that the total area of rectangular field should be 2250 square yards,

$x\cdot y=2250$

We can say that $y=\frac{2250}{x}$

Substituting into the total cost of the rectangular field, we get

$C=20x+8(\frac{2250}{x})\\\\C=20x+\frac{18000}{x}$

We have to figure out where the function is increasing and decreasing. Differentiating,

$\frac{d}{dx}C=\frac{d}{dx}\left(20x+\frac{18000}{x}\right)\\\\C'=20-\frac{18000}{x^2}$

Next, we find the critical points of the derivative

$20-\frac{18000}{x^2}=0\\\\20x^2-\frac{18000}{x^2}x^2=0\cdot \:x^2\\\\20x^2-18000=0\\\\20x^2-18000+18000=0+18000\\\\20x^2=18000\\\\\frac{20x^2}{20}=\frac{18000}{20}\\\\x^2=900\\\\\mathrm{For\:}x^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}x=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}\\\\x=\sqrt{900},\:x=-\sqrt{900}\\\\x=30,\:x=-30$

Because the length is always positive the only point we take is $x=30$ . We thus test the intervals $(0, 30)$ and $(30, \infty)$

$C'(20)=20-\frac{18000}{20^2} = -25 < 0\\\\C'(40)= 20-\frac{18000}{20^2} = 8.75 >0$

we see that total cost function is decreasing on $(0, 30)$ and increasing on $(30, \infty)$ . Therefore, the minimum is attained at $x=30$ , so the minimal cost is

$C(30)=20(30)+\frac{18000}{30}\\C(30)=1200$

The least cost of fencing for the rancher is $1200

Here’s the diagram:

3 0

3 years ago

Please help me! I need help on this question!

schepotkina [342]

Answer:

C and A

Step-by-step explanation:

expand the things in parentheses so for C

1/2(x + 16) = 1/2(x) + 1/2(16) = 1/2 x + 8

same process for A

5 0

3 years ago

(3m^3- 1/2 y) (3m^w - 1/2y)

Brilliant_brown [7]

We use FOIL method to multiply this out. First termsOuter termsInner termsLast terms Product = (3m3 * 3m3) + (3m3 * -1/2y) + (-1/2y * 3m3) + (-1/2y * -1/2y) Product = 9m6 - (3/2)m3y - (3/2)m3y + (1/4)y2 Product = 9m6 - 3m3y + (1/4)y2

6 0

3 years ago