Answer :

To solve the equation [tex]\(5 + \ldots = 9\)[/tex], we can use our knowledge of basic addition facts.

1. Understand the Known Addition Fact:
We know that [tex]\(5 + 4 = 9\)[/tex]. This means that when we add 5 and 4 together, the sum is 9.

2. Apply the Known Information:
In the equation [tex]\(5 + \ldots = 9\)[/tex], we need to determine what number, when added to 5, equals 9.

3. Using the Known Fact:
Since we know from our earlier fact that [tex]\(5 + 4 = 9\)[/tex], we can infer that the number that needs to fill the blank is 4. This is because adding 4 to 5 gives us the sum of 9.

4. Verification:
To verify, we can replace the blank with 4 and check if the equation holds true: [tex]\(5 + 4 = 9\)[/tex]. Yes, 5 plus 4 indeed equals 9.

Thus, knowing that [tex]\(5 + 4 = 9\)[/tex] directly helps us find that the missing number in the equation [tex]\(5 + \ldots = 9\)[/tex] is 4. Therefore, the answer is 4.