Slope help

[Trippy]

I got this slope sheet i gotta do can anyone help me?

Question:
If y varies directly as x and y=3 and x=10, find x when y=8.

Answers:
A. 80 over 3
B. 12 over 5
C. 15 over 4
D. none of these

Any one have any idea on how to do this? appreciate the help.

 

[Mrspi]

I got this slope sheet i gotta do can anyone help me?

Question:
If y varies directly as x and y=3 and x=10, find x when y=8.

Answers:
A. 80 over 3
B. 12 over 5
C. 15 over 4
D. none of these

Any one have any idea on how to do this? appreciate the help.

If y varies directly as x, then
y = kx

You know that y = 3 when x = 10. So,
3 = k*10
3/10 = k

Now, you can write the formula for this specific relationship:
y = (3/10)x

To find the value of x when y = 8, substitute 8 for y and solve for x:
8 = (3/10)x

I'll let you finish it.

 

[Trippy]

thanks you