How many integer values of x satisfy −3 ≤ 2x − 1

Question

How many integer values of x satisfy −3 ≤ 2x − 1 < 5?

Accepted Answer

A. 4. Add 1 to all parts: −2 ≤ 2x < 6. Divide by 2: −1 ≤ x < 3. The integers are −1, 0, 1, 2 — four of them.

Answer

B. 5 — 5 counts x = 3, but 2(3) − 1 = 5, which is NOT less than 5.

Answer

C. 3 — 3 misses x = −1, which is allowed: 2(−1) − 1 = −3, and −3 ≤ −3 is true.

Answer

D. 8 — 8 counts the width of the range for 2x − 1 (from −3 to 5) instead of the integers for x.

Algebra practice question