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3 years ago

Which is NOT a way to state the meaning of the expression x + 2?

Mathematics

1 answer:

lesya692 [45]3 years ago

5 0

2x is not a way to express this. You could use 2 + x or x +2. But 2x is x multiplied by 2. x + 2 is x plus 2.

You might be interested in

Which Property of real numbers does this equation show? 4 x 1 = 4

Colt1911 [192]

Answer:

This is multiplicative identity in which 4✖️1=4

Step-by-step explanation:

Hope it will help you:)

7 0

3 years ago

Please answer this correctly

aleksklad [387]

Answer:

63.2 = y

Step-by-step explanation:

The perimeter is the sum of all the sides

P = 7.8+ y+37.6 + y

171.8 = 7.8+ y+37.6 + y

Combine like terms

171.8 = 45.4 + 2y

Subtract 45.4 from both sides

171.8-45.4 = 45.4 + 2y -45.4

126.4 = 2y

Divide each side by 2

126.4/2 = 2y/2

63.2 = y

6 0

3 years ago

A basketball gymnasium is 25 meters high, 80 meters wide and 200 meters long. We want to connect two strings, one from each of t

Rudiy27

Answer:

a) the centre is at (12.5 m, 40 m , 100 m ) with respect to our position

b) the length of the strings S will be 216.85 m

c) the angle that is formed by the strings is 1.23 rad

Step-by-step explanation:

assuming that we stand on one of the corners on the floor , so our coordinates are (0,0,0) , then the coordinates of the center of the gymnasium are found through

x center = (25 + 0)/2 = 12.5 m

y center = (80+ 0)/2 = 40 m

z center = (200+ 0)/2 = 100 m

then the centre is at (12.5 m, 40 m , 100 m ) with respect to our position

b) the length of the strings S will be the modulus of the vector that points from our position to the diagonally opposite corners

|S| = √(25²+80²+200²) = 216.85 m

c) the angle can be found through the dot product of the vectors that represent the strings S₁ and S₂

S₁ =(25,80,10)

S₂ =(-25,80,100)

then

S₁*S₂ = 25*(-25) +80*80 + 100*100 = 15775

but also

S₁*S₂ = |S₁||S₂| cos θ = |S|² * cos θ

S₁*S₂ = |S|² * cos θ

cos θ= S₁*S₂/|S|²

θ= cos ⁻¹ ( S₁*S₂/|S|² ) = cos ⁻¹ [15775/(25²+80²+200²)] = 1.23 rad

7 0

3 years ago

Marine scientists categorize signature whistles of bottlenose dolphins by typelong dash—type a, type b, type c, etc. In one s

r-ruslan [8.4K]

Answer:

The 95% confidence interval for the true proportion of bottlenose dolphin signature whistles that are type a whistles is (0.4687, 0.6123).

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

$n = 185, \pi = \frac{100}{185} = 0.5405$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.5405 - 1.96\sqrt{\frac{0.5405*0.4595}{185}} = 0.4687$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.5405 + 1.96\sqrt{\frac{0.5405*0.4595}{185}} = 0.6123$

The 95% confidence interval for the true proportion of bottlenose dolphin signature whistles that are type a whistles is (0.4687, 0.6123).

3 0

3 years ago

Kaylee drove 75.5 miles in 54 minutes,if she continues to drive at the same rate, how long will it take her to drive 250 miles?

Crazy boy [7]

Answer:

179 minutes

Step-by-step explanation:

Divide both sides by 75.5 to see how many minutes it would take to drive 1 mile. (54 / 75.5) =108/151
She can drive 1 mile in 108/151 minutes
Times by 250. (108/151 * 250) 178.8
179 to nearest minute

7 0

3 years ago