Evaluate xy-(-2z) for x=10, y=2, and z=-3. a. 6 b. 26 c. 16

Mathematics

2 answers:

Karo-lina-s [1.5K]3 years ago

6 0

B. 26

10*2-(-2*-3)

20-(-2*-3)

20-6

Paul [167]3 years ago

5 0

(10)(2)-(-2)(-3)

20-6

I feel I did this right but its not matching to the answer choices. Does it give anymore information?

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Suppose that diameters of a new species of apple have a bell-shaped distribution with a mean of 7.43cm and a standard deviation

malfutka [58]

Answer:

Approximately 68% of the apples have diameters that are between 7.08cm and 7.78cm.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean of 7.43cm, standard deviation of 0.35cm.

What percentage of the apples have diameters that are between 7.08cm and 7.78cm?

7.43 - 0.35 = 7.08 cm.

7.43 + 0.35 = 7.778 cm.

Within 1 standard deviation of the mean, so approximately 68% of the apples have diameters that are between 7.08cm and 7.78cm.

5 0

2 years ago

(2x+2y=10)+(-x+y=1)

ruslelena [56]

$\bf \begin{cases}
2x+2y=10\\
-x+y=1
\end{cases}\\\\
-------------------------------\\\\
-x+y=1\implies y=1+x\impliedby \textit{let's plug that in the first equation}
\\\\\\
2x+2(\stackrel{y}{1+x})=10\implies 2x+2+2x=10\implies 4x=8
\\\\\\
x=\cfrac{8}{4}\implies \boxed{x=2}\impliedby \textit{let's plug that in the second one}
\\\\\\
-(\stackrel{x}{2})+y=1\implies \boxed{y=3}$