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3 years ago

Brainliest given I got -6 but can someone explain too??

Mathematics

1 answer:

Vesna [10]3 years ago

8 0

Answer:im not good at explanation but i think its -1

Step-by-step explanation:

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3x+5y=-3 x-5y=-5 show your work

frez [133]

We are given the equations 3x+5y=-3 and x-5y=-5.

Both equations have a 5y term which allows us to easily solve the system by elimination. To do so we will add the equations together like a simple addition problem by adding the x terms together, the y terms together, and the integer answers together.

3x + 5y = -3
+x - 5y = -5
---------------
4x + 0y = -8

The y terms cancel out since one is positive and one is negative. Now we can solve for x.

4x = -8

$\frac{4x}{(4)} = \frac{-8}{(4)}$

x = -2

Now plug -2 in for x in one of the original equations to find y.

(-2) - 5y = -5

-5y = -3

y = 3/5

Our answer as an ordered pair is (2, 3/5)

6 0

2 years ago

Help with 21 would be much appreciated.

umka2103 [35]

Answer:

$\large\boxed{x=2\sqrt{21}\ and\ y=4\sqrt3}$

Step-by-step explanation:

Look at the picture.

ΔADC and ΔCDB are similar. Therefore the sides are in proportion:

$\dfrac{AD}{CD}=\dfrac{CD}{DB}$

We have

$AD=14-8=6\\CD=y\\DB=8$

Substitute:

$\dfrac{6}{y}=\dfrac{y}{8}$ <em>cross multiply</em>

$y^2=(6)(8)$

$y^2=48\to y=\sqrt{48}\\\\y=\sqrt{16\cdot3}\\\\y=\sqrt{16}\ cdot\sqrt3\\\\\boxed{y=4\sqrt3}$

For x use the Pythagorean theorem:

$x^2=6^2+(4\sqrt3)^2\\\\x^2=36+48\\\\x^2=84\to x=\sqrt{84}\\\\x=\sqrt{4\cdot21}\\\\x=\sqrt4\cdot\sqrt{21}\\\\\boxed{x=2\sqrt{21}}$

3 0

2 years ago

Let v1 =(-6,4) and v2=(-3,6) compute the following what i sthe angle between v1 and v2

Agata [3.3K]

$\bf ~~~~~~~~~~~~\textit{angle between two vectors }
\\\\
cos(\theta)=\cfrac{\stackrel{\textit{dot product}}{u \cdot v}}{\stackrel{\textit{magnitude product}}{||u||~||v||}} \implies 
\measuredangle \theta = cos^{-1}\left(\cfrac{u \cdot v}{||u||~||v||}\right)\\\\
-------------------------------$

$\bf \begin{cases}
v1=\ \textless \ -6,4\ \textgreater \ \\
v2=\ \textless \ -3,6\ \textgreater \ \\
------------\\
v1\cdot v2=(-6\cdot -3)+(4\cdot 6)\\
\qquad \qquad 42\\
||v1||=\sqrt{(-6)^2+4^2}\\
\qquad \sqrt{52}\\
||v2||=\sqrt{(-3)^2+6^2}\\
\qquad \sqrt{45}
\end{cases}\implies \measuredangle \theta =cos^{-1}\left( \cfrac{42}{\sqrt{52}\cdot \sqrt{45}} \right)
\\\\\\
\measuredangle \theta =cos^{-1}\left( \cfrac{42}{\sqrt{2340}} \right)\implies \measuredangle \theta \approx 29.74488129694^o$

8 0

2 years ago

Heather chops 250 carrots in 2 hours, and 750 carrots in 6 hours. Write an equation that represents the direct relationship betw

Luda [366]

C represents carrots. t represents time in hours.

c= 125t

To find this equation, I found the unit rate, or how many carrots were chooped per hour. I then plugged it into slope intercept form (y=mx+b) where the y intercept was 0 because she can chop 0 carrots in 0 hours.

3 0

3 years ago

Read 2 more answers

The quotient of 1/2 divided by 1 3/4

Alekssandra [29.7K]

Answer:

2/7

Step-by-step explanation:

1 3

1 × 4

2 × 7

4 ÷ 2

14 ÷ 2

6 0

2 years ago