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3 years ago

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write an equation that would allow you to solve the following problem. mart'a jump rope is 10 inches shorter than 3 times the le

ngth of dilbert's rope. if both of their ropes laid together end-to-end measure 120 inches long, how long is Marta's jump rope?

1 answer:

mars1129 [50]3 years ago

8 0

Answer:

Step-by-step explanation:

m=marta's rope

d=dilbert's rope

3d-10=m

m+d=120

Then you can substitute equation 1 into the second one

(3d-10)+d=120

3d-10+d=120

4d-10=120

4d=130

d=32.5

m+d=120

m+32.5=120

m=120-32.5

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Write an equation in slope-intercept form from the points (0, 3) and (-4,-1)

Bezzdna [24]

Answer:

y = x + 3

Step-by-step explanation:

Slope-intercept form is represented by the formula $y = mx + b$ . We can write an equation in point-slope form first, then convert it to that form.

1) First, find the slope of the line. Use the slope formula $m = \frac{y_2-y_1}{x_2-x_1}$ and substitute the x and y values of the given points into it. Then, simplify to find the slope, or $m$ :

$m = \frac{(-1)-(3)}{(-4)-(0)} \\m = \frac{-1-3}{-4-0} \\m = \frac{-4}{-4} \\m = 1$

Thus, the slope of the line must be 1.

2) Now, since we know a point the line intersects and its slope, use the point-slope formula $y-y_1=m(x-x_1)$ and substitute values for $m$ , $x_1$ , and $y_1$ . From there, we can convert the equation into slope-intercept form.

Since $m$ represents the slope, substitute 1 in its place. Since $x_1$ and $y_1$ represent the x and y values of a point the line intersects, choose any one of the given points (either one is fine) and substitute its x and y values into the equation, too. (I chose (0,3).) Finally, isolate y to find the answer:

$y-3=1(x-0)\\y-3 = x\\y = x + 3$

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3 years ago

A bag contains 4 red and 6 green gumballs. if you select 5 of them without looking, how many ways can you get exactly 3 red or e

marusya05 [52]

This is a combination problem. The approach to this is by using the nCr method, where n is the number of total objects and r is the number of success. For example, if you want to get 3 red out of the total 4, then that would be 4C3. That means,

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If you want to get 2 green out of the total 6, then that would be 6C2. That means,

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Therefore, there are a total of 4+15 = <em>19 ways</em>.

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3 years ago

bird a can travel five times as fast as bird B at top speeds of 228 miles per hour what is the fastest speed of bird A and Bird

mart [117]

Answer:

45.6 mph

Step-by-step explanation:

Well,

If Bird A is EXACTLY 5 times as fast as Bird B, then it can reach 228 mph and Bird A can only reach 45.6 mph.

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3 years ago

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The height of a tree in feet over x years is modeled by the function f(x). f(x)=301+29e−0.5x which statements are true about the

Karo-lina-s [1.5K]

Given this equation:

$f(x)=301+29^{-0.5x}$

That represents t<span>he height of a tree in feet over (x) years. Let's analyze each statement according to figure 1 that shows the graph of this equation.
</span>
The tree's maximum height is limited to 30 ft.

As shown in figure below, the tree is not limited, so this statement is false.

<span>The tree is initially 2 ft tall

The tree was planted in x = 0, so evaluating the function for this value, we have:

</span> $f(0)=301+29^{-0.5(0)}=301+1=302ft$
<span>
<span>So, the tree is initially $\boxed{302ft}$ tall.
</span>
Therefore this statement is false.

</span>Between the 5th and 7th years, the tree grows approximately 7 ft.
<span>
if x = 5 then:

</span> $f(5)=301+29^{-0.5(5)}=301ft$ <span>

</span>if x = 7 then:

$f(7)=301+29e^{0.5(7)}=301ft$

So, between the 5th and 7th years the height of the tree remains constant
:
$\Delta=f(7)-f(5)=301-301=0ft$

This is also a false statement.

<span>After growing 15 ft, the tree's rate of growth decreases.</span>

It is reasonable to think that the height of this tree finally will be 301ft. Why? well, if x grows without bound, then the term $29^{-\infty}$ approaches zero.

Therefore this statement is also false.

Conclusion: After being planted this tree won't grow.

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3 years ago

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Jobisdone [24]

Answer:

none of the given options is true

Step-by-step explanation:

Given: u=(-8,8) , v= (-1,2)

To find: vectors $w_1,w_2$ such that $u=w_1+w_2$

Solution:

A vector is a quantity that has both magnitude and direction.

$proj_vu=\frac{u\cdot v}{\left | v \right |^2}(v)\\=\frac{(-8,8)\cdot (-1,2)}{(\sqrt{ (-1)^2+2^2})^2}(-1,2)\\=\frac{8+16}{5}(-1,2)\\=\frac{1}{5}(-24,48)\\=(-4.8,9.6)$

Let $w_1=(-4.8,9.6)$

So,

$w_2=u-w_1\\=(-8,8)-(-4.8,9.6)\\=(-8+4.8,8-9.6)\\=(-3.2,-1.6)$

So, u = $(-4.8,9.6)+(-3.2,-1.6)$

So, none of the given options is true

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3 years ago