y = 3 x equation represents a proportional relationship.
Answer: Option B
<u>Step-by-step explanation:</u>
A proportional variation represents a relationship between two variables x and y. It can be expressed in the form y=k x. Here, the ‘k’, the proportionality constant is equal to the slope m and the line goes through the origin
case A) 
A linear equation that not passes through the origin and so not proportional variation
case B) y= 3 x
Is a linear equation but passes through the origin and so proportional variation
case C) y = - 3x+2
A linear equation that not passes through the origin and so not proportional variation
case D) 
An inverse variation equation but not passes through the origin and so not proportional variation.
From these, equation option B is the proportion equation because in these equations, there is no addition and subtraction of any constant number. That’s why both these equations become proportional equations.
Answer:
$64
Step-by-step explanation:
1/4 means 25%
$48 means 75%
$48 divided by 3 equals 16
$48 plus 16 equals $64
Since this is a right triangle, we can use our trigonometric functions to solve for x.
Since we know the adjacent side and hypotenuse, we will use cosine.
Based on the function

, we can solve for x. The adjacent side is 7 and the hypotenuse is 12. Plugging this in, we get

.
Now, we must use our inverse trigonometric functions to solve for x:

The inverse cosine and cosine on the left side cancel, leaving you with: