Answer:
Four times his sister's age would be 4b. his age is two years less, so we need to subtract 2.
put together, this is 4b - 2.
A factor of 14 is 7, and it isnt a multiple of 2.
7 x 2 = 14
Direct variation is a relation that has the form
y = kx
where k is the constant of proportionality.
If you are told that a relation is a direct proportion, and you are given one data point, you can find k. The you can write the equation of the direct relation.
Here is an example.
The price of gasoline follows a direct variation.
John bought 5 gallons of gas and paid $15.
a) Write an equation for the relation.
b) Using the relation you found, how much do 13.8 gallons cost?
Solution:
Since the relation is a direct variation, it follows the general equation of a direct variation:
y = kx
We are given one data point, 5 gallons cost $15.
We plug in 5 for x and 15 for y and we find k.
y = kx
15 = k * 5
k = 3
Now that we know that k = 3, we rewrite the relation using our value of k.
y = 3x
This is the answer to part a).
Part b)
We use our relation, y = 3x, and we plug in 13.8 into x and find y.
y = 3x
y = 3 * 13.8
y = 41.4
The price of 15 gallons of gas is $41.40.
Theres an infinite amount of numbers because you could have 0.10123 to 0.19998298 its never ending
.9 because the tenth place is 9 and the tenth place for the other one is 8 so its gonna be
.89 < .90 = .9
