The document discusses direct variation in mathematics, explaining that when two quantities have a constant ratio, an increase or decrease in one leads to a corresponding increase or decrease in the other. It highlights the terminology associated with direct variation, such as 'directly proportional' and 'varies directly as.' The relationship between the variables is expressed through the equation y = kx, where k is the constant of variation.

1. WEEK 1-DAY1

4. Mathematics 9

5. 1
2
Illustrate situations that involves Direct
Variation
Translate situations that involves Direct
Variation

6. whenever a situation produces
pairs of numbers in which their
ratio is constant.

7. An increase in one
quantity will cause an
increase to the other at
a common ration

8. An decrease in one
quantity will cause an
decrease to the other
at a common ration

20. “directly proportional to”
“varies directly as”
“is proportional to”

21. y varies directly as x
y = kx