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2 years ago

What is a common denominator for 1/7 and 1/3? a 18 b 21 c 3 d 4

Mathematics

1 answer:

Nataliya [291]2 years ago

6 0

Answer:

B. 21

Step-by-step explanation:

The fractions are there to just make the problem seem complicated, but just rewrite it without the fractions.

"What is a common multiple for 7 and 3?"

In this problem it's easy, all you have to do is guess and check.

A: A doesn't work. 7 is not a factor of 18.

B: B works! Both 3 and 7 are factors of 21.

C: C doesn't work. 7 is not a factor of 3.

D: D doesn't work. Neither are a factor of 4.

They only leave us with one solution, B.

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Which is the slope of the line that passes through the points (3,17) and (7,25)? a slope = 1/2 b slope = 2 c slope = −2 d slope

Ierofanga [76]

Slope is y2-y1/x2-x1
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3 years ago

How do you solve this (5/6)(5/6)

Vikentia [17]

Answer:

25/36

Step-by-step explanation:

Use the top top, bottom bottom method.

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3 years ago

Read 2 more answers

You have D dollars to buy fence to enclose a rectangular plot of land (see figure at right). The fence for the top and bottom co

alex41 [277]

The perimeter of the rectangular plot of land is given by the expression below

$P=2x+2y$

On the other hand, since the available money to buy fence is D dollars,

$\begin{gathered} D=4(2x)+3(2y) \\ \Rightarrow D=8x+6y \\ D\rightarrow\text{ constant} \end{gathered}$

Furthermore, the area of the enclosed land is given by

$A=xy$

Solving the second equation for x,

$\begin{gathered} D=8x+6y \\ \Rightarrow x=\frac{D-6y}{8} \end{gathered}$

Substituting into the equation for the area,

$\begin{gathered} A=(\frac{D-6y}{8})y \\ \Rightarrow A=\frac{D}{8}y-\frac{3}{4}y^2 \end{gathered}$

To find the maximum possible area, solve A'(y)=0, as shown below

$\begin{gathered} A^{\prime}(y)=0 \\ \Rightarrow\frac{D}{8}-\frac{3}{2}y=0 \\ \Rightarrow\frac{3}{2}y=\frac{D}{8} \\ \Rightarrow y=\frac{D}{12} \end{gathered}$

Therefore, the corresponding value of x is

$\begin{gathered} y=\frac{D}{12} \\ \Rightarrow x=\frac{D-6(\frac{D}{12})}{8}=\frac{D-\frac{D}{2}}{8}=\frac{D}{16} \end{gathered}$ <h2>Thus, the dimensions of the fence that maximize the area are x=D/16 and y=D/12.</h2><h2>As for the used money,</h2> $\begin{gathered} top,bottom:\frac{8D}{16}=\frac{D}{2} \\ Sides:\frac{6D}{12}=\frac{D}{2} \end{gathered}$ <h2>Half the money was used for the top and the bottom, while the other half was used for the sides.</h2>

7 0

1 year ago

Please need help asap!!

worty [1.4K]

A property of rectangles is that opposite sides are congruent. In this case, since QT and RS are opposite sides, they are equal to each other. With this knowledge, you can form the equation $50=4x+8$ to solve for x.