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3 years ago

What's the answer to the math problem 8r+4=10+2r

Mathematics

1 answer:

mart [117]3 years ago

6 0

In order to solve for r you have to place all the number in one side. then isolate r ...... r=1

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You discovered 1000 grams of an unknown element called Coolium 23 that has a half life 23 days. How long will it take for you to

Trava [24]

Answer:

13.8 days

Step-by-step explanation:

In this case we can solve it by means of a rule of three, knowing the amount of life for 1000 grams, it must be proportional for 600 grams, like this:

grams days

1000 23

600 x

x = 600 * 23/1000

x = 13.8

which means that for the 600 grams it would be an average life of 13.8 days.

4 0

3 years ago

An island is 1 mi due north of its closest point along a straight shoreline. A visitor is staying at a cabin on the shore that i

Elanso [62]

Answer:

The visitor should run approximately 14.96 mile to minimize the time it takes to reach the island

Step-by-step explanation:

From the question, we have;

The distance of the island from the shoreline = 1 mile

The distance the person is staying from the point on the shoreline = 15 mile

The rate at which the visitor runs = 6 mph

The rate at which the visitor swims = 2.5 mph

Let 'x' represent the distance the person runs, we have;

The distance to swim = $\sqrt{(15-x)^2+1^2}$

The total time, 't', is given as follows;

$t = \dfrac{x}{6} +\dfrac{\sqrt{(15-x)^2+1^2}}{2.5}$

The minimum value of 't' is found by differentiating with an online tool, as follows;

$\dfrac{dt}{dx} = \dfrac{d\left(\dfrac{x}{6} +\dfrac{\sqrt{(15-x)^2+1^2}}{2.5}\right)}{dx} = \dfrac{1}{6} -\dfrac{6 - 0.4\cdot x}{\sqrt{x^2-30\cdot x +226} }$

At the maximum/minimum point, we have;

$\dfrac{1}{6} -\dfrac{6 - 0.4\cdot x}{\sqrt{x^2-30\cdot x +226} } = 0$

Simplifying, with a graphing calculator, we get;

-4.72·x² + 142·x - 1,070 = 0

From which we also get x ≈ 15.04 and x ≈ 0.64956

x ≈ 15.04 mile

Therefore, given that 15.04 mi is 0.04 mi after the point, the distance he should run = 15 mi - 0.04 mi ≈ 14.96 mi

$t = \dfrac{14.96}{6} +\dfrac{\sqrt{(15-14.96)^2+1^2}}{2.5} \approx 2..89$

Therefore, the distance to run, x ≈ 14.96 mile

6 0

3 years ago

The function f is defined by f(x) = (x + 3)(x + 1).

blsea [12.9K]

Answer:

Below in bold.

Step-by-step explanation:

The zeroes ( = x-intercepts) are x = -3 and x = -1.

So the x -coordinate of the vertex is between x = -3 and x = -1.

The actual x-coordinate is halfway between these value: at x = -2.

7 0

3 years ago

Read 2 more answers

Find the percent decrease. Round to the nearest percent.<br><br><br> From 90°F to 70°F

Goryan [66]

Answer:

Step-by-step explanation:

90*x = 70

x = 7/9

x = 78%

100-78 = 22

3 0

3 years ago

Which expression is equivalent to 16x4 – 64? and explain the answer plzz

GuDViN [60]

Answer:

4(4x1-16)

Hope this helps

Have a good day :)

PS I disibuted 4 to 4x1 to get 16 and 4 to -16 to get -64

Step-by-step explanation:

3 0

3 years ago