Translate and solve a word problem.

If three times a number plus four is no more than four times the number minus one, which of the following are true? Let [tex]$z$[/tex] represent the number.

A. [tex]$z\ \textgreater \ 5$[/tex]
B. [tex][tex]$z \geq 5$[/tex][/tex]
C. The number is at least 5.
D. The number is at most 5.



Answer :

Let's carefully translate the given word problem into a mathematical inequality and solve it step by step.

The problem statement says: "Three times a number plus four is no more than four times the number minus one."

Let's denote the unknown number by [tex]\( z \)[/tex].

We translate the statement into an inequality as follows:
[tex]\[ 3z + 4 \leq 4z - 1 \][/tex]

Next, we aim to isolate [tex]\( z \)[/tex] on one side of the inequality. We will start by subtracting [tex]\( 3z \)[/tex] from both sides:
[tex]\[ 3z + 4 - 3z \leq 4z - 1 - 3z \][/tex]
[tex]\[ 4 \leq z - 1 \][/tex]

Then, we add 1 to both sides of the inequality to solve for [tex]\( z \)[/tex]:
[tex]\[ 4 + 1 \leq z - 1 + 1 \][/tex]
[tex]\[ 5 \leq z \][/tex]

Thus, we can write this as:
[tex]\[ z \geq 5 \][/tex]

So, the correct interpretation of the solution to this problem is that the number [tex]\( z \)[/tex] must be at least 5.

Now, let's evaluate which of the given statements are true:

1. [tex]\( z > 5 \)[/tex] — This statement is not true because [tex]\( z \)[/tex] can be exactly 5.
2. [tex]\( z \geq 5 \)[/tex] — This statement is true.
3. 255 — This statement appears to be incorrect and irrelevant to the context.
4. "The number is at least 5." — This statement is true.
5. "The number is at most 5." — This statement is not true because [tex]\( z \)[/tex] can be greater than 5.

Therefore, the true statements are:

- [tex]\( z \geq 5 \)[/tex]
- "The number is at least 5."