Answer:
k = 2
x = 2y
Step-by-step explanation:
If variables x and y vary directly, this is expressed as;
x ∝ y
x = ky
k is the proportionality constant
Let's assume the value of x and y since we are not given;
x = 20
y = 10
Substitute
20 = k(10)
10k = 20
k = 20/10
k = 2
Hence the constant of proportionality is 2
Substitute i=k = 2 into the equation x = ky
x = 2y
Hence an equation that relates x and y is x = 2y
<em>Note that the values here are assumed value, you can use the same method for any values of x and y</em>
A -------------------------------------
A student can take three subjects in 40 ways.
<u>SOLUTION:</u>
Given that, there are 4 different math courses, 5 different science courses, and 2 different history courses.
A student must take one of each, how many different ways can this be done?
Now, number ways to take math course = 4
Number of ways to take science course = 5
Number of ways to take history course = 2
So, now, total possible ways = product of possible ways for each course = 4 x 5 x 2 = 40 ways.
Hence, a student can take three subjects in 40 ways.
It could be B but I want to say D because it relates more to the question.
Answer:
B
Step-by-step explanation: