All categories

4 years ago

The value of y varies directly with x, and y=3 when x=9 find y when x = 21

Mathematics

1 answer:

tester [92]4 years ago

3 0

Answer: y = 7

Step-by-step explanation:

Step 1) plug in 3 for y and 9 for x in the direct variation formula, which is y = kx

3 = k(9)

Step 2) Solve for k

3 = k(9) (Divide by 9 on both sides)

3/9 = k (Now simplify 3/9)

1/3 = k. So k = 1/3

*just FYI: “k” is the constant of variation.

Step 3) use the equation y = kx and plug in 1/3 for k

y = 1/3x

Step 4) using the equation y = 1/3x, plug in 21 for x.

y = 1/3(21) (1/3*21 is the same as 21/3)

y = 21/3 (21/3 = 7)

y = 7. So that’s you’re answer! When x=21, y=7 because 7 is 1/3 of 21!

Hope this helps! My best wishes to you as you go through school!

You might be interested in

What is the answer to 12 + 35 + 24 + 56 + 92 + 16 + 23 x 23 x 45 x 0 ?

8_murik_8 [283]

I will come back to this when I am older

7 0

3 years ago

A clock has a diameter of 16 inches. how far does the hour hand travel during 5 hours? use 3.14 for pi.

valentina_108 [34]

Distance hour hand travel in 5 hours is 20.94 inches.

<h3>What is a diameter?</h3>

A diameter of a circle is any straight line segment that passes through the center of the circle and has endpoints on the circle in geometry.
It is also known as the circle's longest chord.
Both definitions apply to the diameter of a sphere.

To find the distance hour hand travel in 5 hours:

Let's say the hour hand completed one full round around the clock.
If this was the case, it would have been 2 $\pi$ ×8 inches around.
We know that the hour hand only traveled 5 hours around the clock rather than 12, thus our formula is 2 $\pi$ ×8×( 5/12 ).

Distance hour hand travel is 20.94 inches.

Therefore, the distance hour hand travel in 5 hours is 20.94 inches.

Know more diameter here:

brainly.com/question/390660

#SPJ4

8 0

2 years ago

The perimeter of a rectangle is 96 ft. Find the dimensions of the rectangle if the ratio of the length to the width is 7 : 5. Wh

Korolek [52]

Lets say we have a rectangle. if the ratio is 7:5, we can put the width as 7x, and the length as 5x (or vice versa, it doesn't really matter.) If the perimeter is solved by 2(h+w), we have 2(7x+5x)=96, or 2(7x)+2(5x)=96, which is C

4 0

3 years ago

Read 2 more answers

Which equation represents the function graphed on the coordinate plane?????

Y_Kistochka [10]

Since you haven't provided the graph, I'll explain each one and you choose the one suiting your given.

The parent modulus function is:

g(x) = |x|

It is centered at the origin and opens upwards.

A coefficient inside the modulus |x+k| means that the function is shifted along the x-axis

If "k" is positive, the shift will be to the left. If "k" is negative, the shift will be to the right.

A coefficient outside the modulus |x| + h means that the function is shifted along the y-axis

If "h" is positive, the shift will be upwards. If "h" is negative, the shift will be downwards.

Now, let's check each of the options:

g(x) = |x+4| - 2 :

This function is shifted 4 units to the left and 2 units down. It will be centered at (-4,-2). Check the blue graph in the attachment.

g(x) = |x-4| - 2 :

This function is shifted 4 units to the right and 2 units down. It will be centered at (4,-2). Check the black graph in the attachment.

g(x) = |x-2| - 4 :

This function is shifted 2 units to the right and 4 units down. It will be centered at (2,-4). Check the red graph in the attachment.

g(x) = |x-2| + 4 :

This function is shifted 2 units to the right and 4 units up. It will be centered at (2,4). Check the green graph in the attachment.

All 4 graphs are shown in the attached picture.

Hope this helps :)

3 0

3 years ago

Read 2 more answers

William is going on vacation and taking his dog Pickles along. Pickles eats 3 cups of Hungry

prohojiy [21]

Answer:

5 days

Step-by-step explanation:

He eats 3 cups a day and its a 15 cup bag,

15 divided by 3 equals 5.

So he can feed Pickles for 5 days from the bag.

8 0

2 years ago