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2 years ago

−7x−6y=2 7x+4y=−6 solve for x and y

Mathematics

1 answer:

ikadub [295]2 years ago

5 0

Answer:

$\mathrm{The\:solutions\:to\:the\:system\:of\:equations\:are:x=-2,\:y=2}$

Step-by-step explanation:

$\begin{bmatrix}-7x-6y=2\\ 7x+4y=-6\end{bmatrix}$

$\mathrm{Substitute\:}x=-\frac{2+6y}{7}$

$\begin{bmatrix}7\left(-\frac{2+6y}{7}\right)+4y=-6\end{bmatrix}$

$\begin{bmatrix}-2-2y=-6\end{bmatrix}$

$\mathrm{For\:}x=-\frac{2+6y}{7}$

$\mathrm{Substitute\:}y=2$

$x=-\frac{2+6\cdot \:2}{7}\\\\x=-2$

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There are decigrams in 14 hectograms.

dybincka [34]

Answer:

Step-by-step explanation:

14 Decigrams = 0.014 Hectograms

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3 years ago

If the smallest angle of a triangle is 20° and it is included between sides of 4 and 7, then (to the nearest tenth) the smallest

lawyer [7]

Answer:

$3.5$

Step-by-step explanation:

The smallest side of a triangle is formed by the smallest angle in the triangle.

To find the side opposite (formed by) the 20 degree angle, we can use the Law of Cosines. The Law of Cosines states that for any triangle, $c^2=a^2+b^2-ab\cos \gamma$ , where $a$ , $b$ , and $c$ are the three sides of the triangle and $\gamma$ is the angle opposite to $c$ .

Let $c$ be the side opposite to the 20 degree angle.

Assign variables:

$a\implies 4$
$b\implies 7$
$\gamma \implies 20^{\circ}$

Substituting these variables, we get:

$c^2=4^2+7^2-2(4)(7)\cos 20^{\circ},\\c^2=16+49-56\cos 20^{\circ},\\c^2=12.377213236,\\c=\sqrt{12.377213236}=3.51812638147\approx \boxed{3.5}$

Therefore, the shortest side of this triangle is 3.5.

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3 years ago

Ratio is 4:7, smaller volume is 1, 331, find larger volume

viva [34]

If the smaller volume ratio is 4 to 1331, divide 1331 by 4 to get the multiplying factor.
1331/4 = 332.75
Now we multiply 332.75 by 7 to get our larger volume.
332.75 x 7 = 2329.25
2,329 is our larger volume.
I hope this helps!

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3 years ago

pleas help I need help with these two! right answers only please asap! will give brainliest to person who explains !

ladessa [460]

For question 4: you have to do (y2 - y1) divided by (x2 - x1) to get the rise over run...

5-2
——. = 3/4
11 - 7

For question 5: input the values of x,y and the gradient into the equation of a line.....

y = mx+ c

-8 = 3(-2) + c

-8 = -6 + c

-2 = c

therefore:

y = 3x - 2

Hope this helps! Any questions let me know :)

7 0

3 years ago

Read 2 more answers

All members of our painting team paint at the same rate. If $20$ members can paint a $4800$ square foot wall in $36$ minutes, th

Softa [21]

Answer:

It takes 70 minutes for 9 team members (painting 60 sq ft per minute) to paint a 4200 sq ft wall.

Step-by-step explanation:

According to the situation the calculation is shown below:-

= $\frac{4800}{20}$