Suppose y varies directly with x. Write a direct variation equation that relates x and y. Then find the value of y when x = 7.

2 answers:

5 0

From the statement, y varies directly with x. It can be expressed as:

y α x

To change it to an equality, we insert a proportionality constant k.

y = kx

We first solve for k,

8 = k(-4)
k = -2

Therefore, when x = 7,

y = -2(7)
y = -14

Sonja [21]3 years ago

4 0

For direct variation, y = kx
8 = -4k
k = 8/-4 = -2

Therefore, required equation is y = -2x

when x = 7, y = -2(7) = -14

You might be interested in

Find a number which decreased by 12 equals 3 times it’s opposite

-BARSIC- [3]

Answer:

The number is 3.

Step-by-step explanation:

To find : A number which decreased by 12 equals 3 times it’s opposite ?

Solution :

Let the number be 'x'.

It's opposite is '-x'.

A number which decreased by 12 equals 3 times it’s opposite

i.e. $x - 12 = 3(-x)$

Solving the equation,

$x-12=-3x$

$x+3x=12$

$4x=12$

$x=\frac{12}{4}$

$x=3$

Therefore, the number is 3.

4 0

2 years ago

What is the distance between the points (4,-2) and )-5,3)?

abruzzese [7]

Answer:

10.3

Step-by-step explanation:

Let the given points be the endpoints of a right triangle. The horizontal change in x is from 4 to -5 and is negative 9; the vertical change in y is from -2 to+ 3 and is +5.

The desired distance is found using the Pythagorean theorem:

d = √(9² + 5²) = √106, or 10.3 (to the nearest tength)

3 0

3 years ago

Find the possible values for m<1

Anuta_ua [19.1K]

0.5 that would be half of one if one is greater than the variable M

I really hope this helped ... have a great day !

4 0

2 years ago

The ratio 5.2 to 2.8 is ? Write the following ratio in simplest form

drek231 [11]

I believe the ratio in simplest form is 1.3 to 0.7.