Final answer:
Options a (x=1) and b (x=2) satisfy the inequality 7x < 21 since both are less than 3 when the inequality is simplified to x < 3. Option c (x=3) does not satisfy the inequality as it is equal to 3, not less.
Step-by-step explanation:
The question is asking us to determine which of the given x-values satisfies the inequality 7x < 21. To do this, we can divide both sides of the inequality by 7, which simplifies it to x < 3. With this simplified inequality, we can now evaluate which options are less than 3:
For option a, x=1, we see that 1 is indeed less than 3, so this value satisfies the inequality.
For option b, x=2, this value is also less than 3, so it too satisfies the inequality.
For option c, x=3, since 3 is not less than 3 (it is equal), this value does not satisfy the inequality.
Therefore, the x-values that satisfy the inequality 7x < 21 are options a and b: x=1 and x=2.