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3 years ago

Help me please. Not sure how to solve this. Can someone show me how to do it step by step. -2/5x-9<9/10

1 answer:

7 0

Leave the x alone first. -2/5x<9/10+9. then -2/5×<99/10. multiply both sides by 5 you'll get -99/2 < 2x. then divide both sides by 2 you'll get -99/4 < ×

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What does the expression l+w+l+w represent

djverab [1.8K]

That means legthn+lgnth +width+width

that is the perimeter formula for a rectangle or the measure around a rectangle

it can be written as (l-legnth)
perimiter=2l+2w or
p=2l+2w or
p=2(l+w)

5 0

3 years ago

Read 2 more answers

Please please Help me!!!!!

pav-90 [236]

Answer:

19,23

Step-by-step explanation:

9+x-7≥ 21

Combine like terms

2+x≥21

Subtract 2 from each side

2+x-2 ≥21-2

x≥19

Any number greater than or equal to 19

3 0

3 years ago

Batteries produced by a manufacturing company have had a life expectancy of 135 hours. Because of an improved production process

Nikolay [14]

Answer: c. z = 1.35; Reject the null hypothesis

Step-by-step explanation:

Let $\mu$ be the average life expectancy of its batteries.

As per given , we have

Null hypothesis : $H_0 : \mu =135$

Alternative hypothesis : $H_a : \mu >135$

Since $H_a$ is right-tailed and population standard deviation is also known, so we perform right-tailed z-test.

Test statistic : $\dfrac{\overlien{x}-\mu}{\dfrac{\sigma}{\sqrt{n}}}$

where, n= sample size

$\overlien{x}$ = sample mean

$\mu$ = Population mean

$\sigma$ =population standard deviation

For $n=42,\ \overline{x}=140\ \&\ \sigma=24$ , we have

$z=\dfrac{140-135}{\dfrac{24}{\sqrt{42}}}=1.35015431217\approx1.35$

Critical one-tailed test value for 0.10 significance level :

$z_{0.1}=1.28$

Decision : Since critical z value (1.28) < test statistic (1.35), so we reject the null hypothesis .

[When critical value is less than the test statistic value , we reject the null hypothesis .]

5 0

3 years ago

Martine’s town is building a volleyball court based on a scale drawing that is 40cm to 80cm and uses the scale 1cm:22.5cm write

never [62]

Answer:

$y=22.5x$

Step-by-step explanation:

we have that

The scale drawing is

$\frac{1}{22.5}\frac{cm}{cm}$

we know that

Using proportion find out the actual dimensions of the volleyball court

Let

x -----> drawing court lengths in cm

y ----> court lengths in cm

For x=40 cm

$\frac{1}{22.5}\frac{cm}{cm}=\frac{40}{y}\frac{cm}{cm}\\\\y=40*22.5\\\\y=900\ cm$

For x=80 cm

$\frac{1}{22.5}\frac{cm}{cm}=\frac{80}{y}\frac{cm}{cm}\\\\y=80*22.5\\\\y=1,800\ cm$

Find the equation for the proportional relation ship between drawing court lengths x in centimeters and court lengths in y centimeters

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form $y/x=k$ or $y=kx$

For x=40 cm, y=900

substitute

$k=y/x$ -----> $k=900/40=22.5$

The equation is

$y=22.5x$

5 0

3 years ago

Victoria has $200 of her birthday gift money saved at home, and the amount is modeled by the function h(x) = 200. She reads abou

san4es73 [151]

Answer:

h(x) * s(x) = 200(1.05)^(x - 1)

Step-by-step explanation:

Our interest equation is s(x) = (1.05)^(x - 1). This is actually a part of a bigger formula for calculating the amount of money accumulated including interest:

A = P(1 + r)^n, where A is the total, P is the principal amount (initial amount), r is the interest rate, and n is the time

Here, we technically already have the (1 + r)^n part; it's just (1.05)^(x - 1). The principle, though, will actually be the 200 because she starts out at $200.

Thus, to combine these, we simply multiply them together to get:

h(x) * s(x) = 200(1.05)^(x - 1)

4 0

3 years ago

Read 2 more answers