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3 years ago

Solve each equation using elimination. 2a+3b=12 5a- b=13

1 answer:

8 0

$\left \{ {{2a+3b=12} \atop {5a-b=13\ \ | *3}} \right. \\\\ \left \{ {{2a+3b=12} \atop {15a-3b=39}} \right. \\+-----\\ add\ both\ equations\\\\
17a=51\ \ \ | divide\ by\ 17\\\\
a=3\\\\
b=5a-13\\\\
b=5*3-13=15-13=2\\\\
b=2$

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The base of a cone shaped glass is 12 inches and it is 18 inches tall, what is the volume

Maslowich

216. All you have to do to find volume is to multiply the numbers. 12 x 18 = 216.

5 0

3 years ago

pH measurements of a chemical solutions have mean 6.8 with standard deviation 0.02. Assuming all pH measurements of this solutio

aalyn [17]

Answer: 2.14 %

Step-by-step explanation:

Given : pH measurements of a chemical solutions have

Mean : $\mu=6.8$

Standard deviation : $\sigma=0.02$

Let X be the pH reading of a randomly selected customer chemical solution.

We assume pH measurements of this solution have a nearly symmetric/bell-curve distribution (i.e. normal distribution).

The z-score for the normal distribution is given by :-

$z=\dfrac{x-\mu}{\sigma}$

For x = 6.74

$z=\dfrac{6.74-6.8}{0.02}=-3$

For x = 6.76

$z=\dfrac{6.76-6.8}{0.02}=-2$

The p-value = $P(6.74$

$P(z$

In percent, $0.0214\times=2.14\%$

Hence, the percent of pH measurements reading below 6.74 OR above 6.76 = 2.14%

6 0

3 years ago

The points (-4, 3) and (4, r) lie on a line with slope 1/2<br> Find the missing coordinate r.

melisa1 [442]

Answer:

Step-by-step explanation:

8 units separate -4 and 4

8 divided by 2 (which is the x of slope) is four

Four times 1 (which is y of slope) equals four

3+4 equals seven

(4,7)

7 0

3 years ago

Solve for the value of X as you should solve for X and explain.

Varvara68 [4.7K]

Answer:

12cos59, about 6.18

Step-by-step explanation:

cos59 = x/12

(adjacent/hypotenuse)

x = 12cos59

plugging this into a calculator gets you about 6.18

6 0

2 years ago

Find the equation of the line that passes through points (4,5) and (-1,6).

steposvetlana [31]

First find the slope using the formula $m= \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$
Substitute the values in:
$m= \frac{6-5}{-1-4}= -\frac{1}{5}$
Point-slope form is $y=m(x-x_{1})+y_{1}$
Substitute (it doesn't matter which point you choose; I chose (4,5):
$y=- \frac{1}{5} (x-4)+5=-\frac{1}{5}x+\frac{29}{5}$
Therefore, the answer is D. $y=-\frac{1}{5}x+\frac{29}{5}$

4 0

3 years ago