Measureing midpoints

4a/3-b/4=6 5a/6+b=13 Solve linear system by elimination

kondor19780726 [428]

$\bf \cfrac{4a}{3}-\cfrac{b}{4}=6
\qquad \qquad 
\cfrac{5a}{6}+b=13
\\\\\\
\textit{let us remove the denominators off those folks}\\
\textit{by multiplying the first one by 12, both sides}\\
\textit{and the second one by 6, both sides, thus}
\\\\\\
12\left( \cfrac{4a}{3}-\cfrac{b}{4} \right)=12(6)\implies 16a-4b=72
\\\\\\
6\left( \cfrac{5a}{6}+b \right)=6(13)\implies 5a+6b=78$

$\bf \textit{now, let's do the elimination}
\\\\

\begin{array}{llll}
16a-4b=72&\boxed{\times 3}\implies &48a-\underline{12b}=216\\\\
5a+6b=78&\boxed{\times 2}\implies &10a+\underline{12b}=156\\
&&--------\\
&&58a+0\quad=372
\end{array}$

solve for "a", once you get "a", plug it back into either equation to get "b"

3 0

3 years ago

A test consists of 100 multiple choice questions, each with five possible answers, only one of which is correct. Find the mean a

TEA [102]

Answer: Mean = 20 and standard deviation = 4

Step-by-step explanation:

Let x represents the success of getting the correct answer.

Here, the total number of trials(n) = 100

The probability of getting the correct answer, p = 1/5

Thus, the mean of the number of correct answer,

$\mu_x= np$

$\mu_x= 100\times 1/5$

$\mu_x= 20$

Now, the standard deviation, $\sigma_x= \sqrt{n\times p\times (1-p)}$

$\sigma_x= \sqrt{100\times 1/5\times 4/5}$

$\sigma_x= \sqrt{16}$

$\sigma_x= 4$

Thus, First option is correct.

6 0

3 years ago

What type of polygon would a slice of a hexahedron at a vertex create? Explain. What type of polygon would a slice of an icosahe

harina [27]

Answer:

hexahedron: triangle or quadrilateral or pentagon
icosahedron: quadrilateral or pentagon

Step-by-step explanation:

Hexahedron

A hexahedron has 6 faces. A regular hexahedron is a cube. 3 square faces meet at each vertex.

If the hexahedron is not regular, depending on how those faces are arranged, a slice near a vertex may intersect 3, 4, or 5 faces. The first attachment shows 3- and 4-edges meeting at a vertex. If those two vertices were merged, then there would be 5 edges meeting at the vertex of the resulting pentagonal pyramid.

A slice near a vertex may create a triangle, quadrilateral, or pentagon.

Icosahedron

An icosahedron has 20 faces. The faces of a regular icosahedron are all equilateral triangles. 5 triangles meet at each vertex.

If the icosahedron is not regular, depending on how the faces are arranged, a slice near the vertex may intersect from 3 to 19 faces.

A slice near a vertex may create a polygon of 3 to 19 sides..

3 0

3 years ago

PLEASE help me with these 2 questions!!

dimaraw [331]

You do not want the "b" since two of the equations start off at 0 kites.

x=kites purchased

Kities : y=8x

Windy Kites: y=20x

From there, all you need to do is plug in the kite purchased number replacing x.

4 0

3 years ago

I need help with this

azamat

Answer:

Let the amount of Danny be y

Therefore, lance will have 1/3y

Total fraction of cup is 1/1

y+y/3=1

4y/3=1

4y=3

y=3/4

therefore, lance had 3/4 of the cup of water

4 0

3 years ago