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2 years ago

4(x+3)-(2x-1)=30+7x-1+5x

Mathematics

2 answers:

denis23 [38]2 years ago

8 0

x= -8/5

x equals negative 8 over 5

aivan3 [116]2 years ago

8 0

4(x+3)-(2x-1)=30+7x-1+5x

distribute

4x+12 -2x+1 =30 +7x-1+5x

combine like terms

2x+13 = 29+12x

subtract 2x from each side

13 =29+10x

subtract 29 from each side

-16= 10 x

divide by 10

-1.6 =x

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Fernando loves to make music playlists. He likes to keep the same ratio of country songs to rock songs. On his summer playlist,

Ede4ka [16]

Answer:

There are 6 rock songs on Fernando's road trip playlist.

Step-by-step explanation:

Given that he keeps the ratio same

This means that the ratios for both summer playlist and trip playlist will be the same

Let

c1 be the country songs in summer playlist

r1 be the rock songs in trip playlist

Similarly,

c2,r2 will be the country and rock songs in trip playlist

Both will be equal so

$\frac{c_1}{r_1} = \frac{c_2}{r_2}$

Putting the values

$\frac{100}{24} = \frac{25}{r_2}\\100r_2 = 25*24\\100r_2 = 600r_2 = \frac{600}{100}\\r_2 = 6$

Hence,

There are 6 rock songs on Fernando's road trip playlist.

3 0

2 years ago

Please help me with precalculus?? linear and angular speed

Anit [1.1K]

13)

there are 2π radians in 1 revolution, and there are 60 seconds in 1 minute, so keeping that in mind, then,

$\bf \cfrac{4\underline{\pi} }{5~\underline{s}}\cdot \cfrac{rev}{2\underline{\pi} }\cdot \cfrac{60~\underline{s}}{min}\implies \cfrac{4\cdot 60~rev}{5\cdot 2~min}\implies \cfrac{240~rev}{10~min}\implies 24\frac{rev}{min}$

14)

$\bf \textit{linear velocity}\\\\
v=rw\quad 
\begin{cases}
r=radius\\
w=angular~speed\\
----------\\
v=32\frac{m}{sec}\\
w=100\frac{rev}{min}
\end{cases}\\\\
-------------------------------\\\\
\textit{let's convert \underline{w} to }\frac{radians}{sec}$

$\bf \cfrac{100~\underline{rev}}{\underline{min}}\cdot \cfrac{2\pi }{\underline{rev}}\cdot \cfrac{\underline{min}}{60~sec}\implies \cfrac{100\cdot 2\pi }{60~sec}\implies \cfrac{10\pi }{3~sec}\implies \cfrac{10\pi }{3}\frac{radians}{sec}\\\\
-------------------------------\\\\
v=rw\implies \cfrac{v}{w}=r\implies \cfrac{\frac{30~m}{sec}}{\frac{10\pi }{3~sec}}\implies r=\cfrac{30~m}{\underline{sec}}\cdot \cfrac{3~\underline{sec}}{10\pi }
\\\\\\
r=\cfrac{90}{10\pi }m$

15)

what is the radians per seconds "w" in revolutions per minute? just another conversion like in 13)

$\bf \cfrac{\underline{\pi} }{3~\underline{sec}}\cdot \cfrac{rev}{2\underline{\pi }}\cdot \cfrac{60~\underline{sec}}{min}\implies \cfrac{60 ~rev}{3\cdot 2 ~min}\implies \cfrac{60 ~rev}{6 ~min}\implies 10\frac{rev}{min}$

4 0

3 years ago

We are currently learning triangle similarity and about dilations in geometry. We have been using cross multiplying to figure th

miss Akunina [59]

Took me a minute to think.

Form ratios.

x, the small triangle, forms a ratio with 6, the big triangle.

The part of the side that is equal(with the dash) that is part of the small triangle is equal to 6-x, the big triangle.

Yes, you can cross-multiply here!

$\frac{6}{x} = \frac{8}{6-x}$

Now, cross multiply.
P.S. Use distributive property.

36-6x = 8x

Add 6x on both sides.

36=14x

Divide by 14 on both sides.

x = $\frac{36}{14}$ = $\frac{18}{7}$

4 0

3 years ago

Plz help!!

inysia [295]

1. 5564÷91
I know that 9 * 6 = 56
5564 rounds to 5600
91 rounds to 9
Since 56/9 = 6, then 5600/90 is the same as 560/9 = 60
The estimate is 60

2. 5391÷25
5391 sounds to 5400
25 is 1/4 of 100.
That means when you divide by 25, you can divide by 100 and multiply by 4.
5400/100 = 54
54 * 4 = 216
Estimate: 216

3. explain how to estimate 498÷12
48/12 = 4
498 is little more than 480, so 498/12 is little more than 40

4. which is the closest estimate for 2130÷ 33
A.7 B.17 C.70 D.700

2130/33
Round off the numerator and denominator to
2100/30
Reduce the fraction
210/3
Since I know that 21/3 = 7, then 210/3 = 70
Estimate: 70

8 0

3 years ago

The Precision Scientific Instrument Company manufactures thermometers that are supposed to give readings of 0degrees°C at the fr

Sergio039 [100]

Answer:

Step-by-step explanation:

Hello!

The variable of study is X: Temperature measured by a thermometer (ºC)

This variable has a distribution approximately normal with mean μ= 0ºC and standard deviation σ= 1.00ºC

To determine the value of X that separates the bottom 4% of the distribution from the top 96% you have to work using the standard normal distribution:

P(X≤x)= 0.04 ⇒ P(Z≤z)=0.04

First you have to use the Z tables to determine the value of Z that accumulates 0.04 of probability. It is the "bottom" 0.04, this means that the value will be in the left tail of the distribution and will be a negative value.

z= -1.75

Now using the formula of the distribution and the parameters of X you have to transform the Z-value into a value of X

z= (X-μ)/σ

z*σ = X-μ

(z*σ)+μ = X

X= (-1.75-0)/1= -1.75ºC

The value that separates the bottom 4% is -1.75ºC

I hope this helps!

5 0

3 years ago