Reading the question, we can see that there are two unknowns:
1) x which represents a generic number
2) another number, say y, that is 8 less than twice x.
Now let's answer the question. We need to write an expression for y. We know y is 8 less than twice x. Twice x is 2*x or simply 2x. But since y is 8 less than 2x, the answer to the question is:
y < 2x - 8