Question

y and x have a proportional relationship, and y = 12 when x = 5. What is the value of y when x = 8?

y and x have a proportional relationship, and y = 7 when x = 2. What is the value of x
when y = 21?


Which equation represents a proportional relationship?

y=12x

y=2(x+13)

y=−3x+2

y = 3x

Answer 1

1st question: y=19.2. because x=8 when x multiply by 1.6, so y should multiply by 1.6 to get 19.2
2nd question: x=6. Because y multiply by 3 is 21, so x need to multiply by 3 to get 6.
Sorry I don’t know the third question.....