Question

I have 2 questions that I need help with if someone could please help me step by step to figure out how to do this equation it would be very helpful. Thank you
1. Suppose y varies directly with x and, y=15 and x=5. Write a direct variation equation that relates x and y. What is the value of y when x=9?
2. Write the equation in standard form using integers (no fractions or decimals.): y=-2/3x-1
I'm not really sure at all with this one is it y=-2/3(0)-1 Thank you

Answer 1

The statement " y varies directly as x ," means that then x increases,y increases by the same factor so we have: y/x=k
for question 1 then: 15/5=3
so the direct variation equation is y=3x
Now if x=9 you only have to replace x in your equation and you get:
y=3*9=27