Answer:
(a) x = -2y
(c) 3x - 2y = 0
Step-by-step explanation:
You can tell if an equation is a direct variation equation if it can be written in the format y = kx.
Note that there is no addition and subtraction in this equation.
Let's put these equations in the form y = kx.
(a) x = -2y
- y = x/-2 → y = -1/2x
- This is equivalent to multiplying x by -1/2, so this is an example of direct variation.
(b) x + 2y = 12
- 2y = 12 - x
- y = 6 - 1/2x
- This is not in the form y = kx since we are adding 6 to -1/2x. Therefore, this is <u>NOT</u> an example of direct variation.
(c) 3x - 2y = 0
- -2y = -3x
- y = 3/2x
- This follows the format of y = kx, so it is an example of direct variation.
(d) 5x² + y = 0
- y = -5x²
- This is not in the form of y = kx, so it is <u>NOT</u> an example of direct variation.
(e) y = 0.3x + 1.6
- 1.6 is being added to 0.3x, so it is <u>NOT</u> an example of direct variation.
(f) y - 2 = x
- y = x + 2
- 2 is being added to x, so it is <u>NOT</u> an example of direct variation.
The following equations are examples of direct variation:
Answer:
7x = 35cm ; 2x = 10cm
Step-by-step explanation:
7x and 2x are the lengths
7x+2x=45
Then you take 7 + 2 = 9
so is gonna be 9x = 45
then you divide both side with 9
so is gonna be x = 5
Then you take 5 multiply 7 : 2
so 7 x 5 = 35cm
2 x 5 = 10cm
Answer:
C.) 2
Step-by-step explanation:
<em>You must use the pythagorean theorem</em>
the distance on the x axis (or a) is 6
the distance on the y axis (or b) is 10
= 136
= 2
<h3>
Answer: 11 cans</h3>
======================================================
Explanation:
SA = surface area of the sphere
SA = 4*pi*r^2
SA = 4*pi*8^2
SA = 804.247719
The surface area is roughly 804.247719 sq ft.
I used the calculator's stored version of pi to get the most accuracy possible.
Since 1 paint can covers 75 sq ft, divide that surface area over 75 to find out how many cans you need.
804.247719/75 = 10.72330292
Round up to the nearest integer to get 11
You'll have leftover paint, but it's better to go over the goal than come up short.
