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:
4 : 9
Step-by-step explanation:
The requested ratio is ...
tile length : board length = (2/3 ft) : (1/2 yd) = (8 in) : (18 in)
= 8 : 18 = 4 : 9
_____
To make a unitless ratio, both parts must have the same units. Here, we chose to express the lengths in inches. We could have used feet or yards as well. (2/3 ft)×(1 yard)/(3 ft) = 2/9 yd or (1/2 yd)(3 ft/yd) = 3/2 ft. You get the same ratio with any of these:
(2/9 yd) : (1/2 yd) = (4 yd) : (9 yd) = 4 : 9 . . . . . multiply by 18
(2/3 ft) : (3/2 ft) = (4 ft) : (9 ft) = 4 : 9 . . . . . multiply by 6
The answer is 95 degrees because it is a vertical angle. This is actually a lot easier than it looks. Hope this helped.
Answer:
960cm³
Step-by-step explanation:
Find the base of the triangle (use phytagoras theorem)
c²= a²+b²
20²= 16²+b²
400=256+b²
b²=400-256
b²= 144
b=
base= 12
Volume: (1/2×b×h)×l
= (1/2×12×16)×10
=(6×16)×10
=96×10
=960cm³
Answer: 0.55
Step-by-step explanation:
