Answer:
y=kx
subst y=10 and x=20 into the above
<em>1</em><em>0</em><em>=</em><em>k20</em>
<em>k</em><em>=</em><em>1</em><em>0</em><em>/</em><em>2</em><em>0</em>
<em>k</em><em>=</em><em>1</em><em>/</em><em>2</em>
<em>therefore</em><em> </em><em>relationship</em><em>:</em><em> </em><em>y</em><em>=</em><em>1</em><em>/</em><em>2</em><em>x</em>
<em>subst</em><em> </em><em>x</em><em>=</em><em>1</em><em>5</em><em> </em><em>into</em><em> </em><em>the</em><em> </em><em>relationship</em>
<em> </em><em>y</em><em>=</em><em>1</em><em>/</em><em>2</em><em>(</em><em>1</em><em>5</em><em>)</em>
<em>y</em><em>=</em><em>7</em><em>,</em><em>5</em>
Step by step explanation:
- Step 1: when they say y varies directly with x they mean<em> y is proportional to x</em>
- step 2: so y=kx where <em>k is the constant</em>
- step 3: is to substitute <em>y=10</em> and <em>x=20</em> into the above equation y=kx
- step 4: you will end up with <em>10=k20</em> then divide both sides by 20 so that <em>k becomes the subject of the formula </em>
- step 5: your answer from the above will be <em>k=10/20 </em>so the relationship is <em>y is directly proportional to 1/2 x </em>what you did here is that you substituted k for 1/2 in the equation in step 3
- step 6: is to finally substitute x=15 into the equation <em>y=1/2x</em> to finally get your answer <em>y</em><em>=</em><em>7</em><em>,</em><em>5</em><em>.</em>
The circumference of the new disc 160Π that is 10 time of old circumference.
Step-by-step explanation:
Given,
Circumference of circular disc = 16Π (pi = Π)
Let, the radius of the circle be 'r'
Formula
The circumference of a circle with r radius = 2 Π r
According to the problem,
2 Π r = 16Π
or, 2r = 16 ( by eliminating the value of Π from both the side)
or, r = 8
Now, we multiply the radius by 10
so, the new radius is 8 X 10 = 80
Now the circumference = 2 Π X 80
= 160Π
Hence, the new circumference also will be 10 times of the older one.
Answer: t=-3h+25
Step-by-step explanation:
t=-3h+25
25 degrees is a constant-- it never changes, no matter how many hours goes by. So, you don't multiply a variable with it.
The temperature drops every 3 hours-- this is not constant, since it's dependent on the number of hours that passes. So, use a variable here. Since the temperature drops every three hours, it's -3, and not 3.
