Given: 3x – t = t + 5x
Target question: What is the value of x ?
Statement 1: t = 4
Take: 3x – t = t + 5x
Replace t with 4 to get: 3x – 4 = 4 + 5x
When we solve this equation, we get x = -4
Since we can answer the target question with certainty, statement 1 is SUFFICIENT
Statement 2: x < 0
If x < 0, then x can have infinitely-many different values
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
