Direct Variation

What does it mean if two quantities are directly proportional?

• It means that the ratio of the two quantities remains constant.

• It means that the two quantities are equal.

• It means that one quantity increases while the other decreases.

• It means that the two quantities are unrelated.

If y varies directly with x and y = 12 when x = 15, what is the constant of proportionality k?

• 0.5

• 0.6

• 0.8

• 1.0

What is the constant of proportionality in the equation y = 7x?

• 5

• 7

• 10

• 3

What is the significance of the origin in the graph of direct variation?

• It indicates that when x = 0, y must also be 0.

• It shows the maximum value of y when x is at its peak.

• It represents the point where the graph intersects the y-axis.

• It is the point where all values of x and y are negative.

What is an example of a direct variation in real life?

• The relationship between distance and time when traveling at a constant speed.

• The relationship between the amount of rainfall and the growth of plants.

• The relationship between the number of hours studied and the score on a test.

• The relationship between the temperature and the amount of ice in a drink.

How can you determine if a set of points represents a direct variation?

• If the points form a straight line that passes through the origin, they represent a direct variation.

• If the points form a curve, they represent a direct variation.

• If the points are all positive, they represent a direct variation.

• If the points are evenly spaced, they represent a direct variation.

What is the formula to find the constant of proportionality k?

• k = y/x, where y is the dependent variable and x is the independent variable.

• k = x/y, where y is the dependent variable and x is the independent variable.

• k = y + x, where y is the dependent variable and x is the independent variable.

• k = y - x, where y is the dependent variable and x is the independent variable.

What is the relationship between x and y in direct variation?

• As x increases, y remains constant.

• As x increases, y increases proportionally, and as x decreases, y decreases proportionally.

• There is no relationship between x and y in direct variation.

• As x decreases, y increases proportionally.

If y = 2x and x = 10, what is y?

• 10

• 15

• 20

• 25

What is Direct Variation?

• A relationship where one variable is a constant multiple of the other, expressed as y = kx, where k is the constant of proportionality.

• A relationship where two variables are equal to each other, expressed as y = x.

• A relationship where one variable increases while the other decreases, expressed as y = k/x.

• A relationship that describes the sum of two variables, expressed as y = x + k.