Which is a solution to the equation y=5x-6

A "solution" is a pair of numbers that can be written in place of 'x' and 'y' and make the equation a true statement.

For example . . . Is (x=1, y=2) a solution ?
To find out, write '1' in place of 'x', and write '2' in place of 'y'.

y = 5x - 6
2 = 5(1) - 6
2 = 5 - 6
Is that true ?  NO ! ! !
So (x=1, y=2) is NOT a solution to this equation.

But hold onto your seat . . . there ARE an infinite number of solutions.
You can draw a graph of the equation. The graph is a straight line,
and EVERY POINT on the line is a solution to the equation.
(Do you have any idea how many points there are on a line ? ! ?)

Since your question begins with the word "Which...", I know there was a
list of choices along with it, in the book or on the homework or wherever
you copied the question from, and you decided not to share the list.  So
nobody can answer the question, because we don't know which choice
on the list is the correct one.

I'll just give you a few solutions to the equation, out of the infinite number
of them that there are:

Each of these lines is 1 solution:

x= -1, y= -11
x=0, y= -6
x=1, y= -1
x=2, y= 4
x=5, y= 19
x=100, y= 494

The scale factor of what ?