Answer :

To find the two numbers, we can set up two equations based on the given conditions:

1. The sum of the two numbers is 90.
2. The difference of the two numbers is 12.

Let's call the two numbers [tex]\(x\)[/tex] and [tex]\(y\)[/tex].

From the conditions, we have:
1. [tex]\(x + y = 90\)[/tex]
2. [tex]\(x - y = 12\)[/tex]

We can solve these equations step-by-step:

Step 1: Add the two equations

When we add the two equations, we get:
[tex]\[ (x + y) + (x - y) = 90 + 12 \][/tex]

Simplify the left side of the equation:
[tex]\[ 2x = 102 \][/tex]

Divide both sides by 2 to solve for [tex]\(x\)[/tex]:
[tex]\[ x = \frac{102}{2} = 51 \][/tex]

Step 2: Substitute the value of [tex]\(x\)[/tex] back into one of the original equations

We can use the first equation [tex]\(x + y = 90\)[/tex]:
[tex]\[ 51 + y = 90 \][/tex]

Subtract 51 from both sides to solve for [tex]\(y\)[/tex]:
[tex]\[ y = 90 - 51 = 39 \][/tex]

So, the two numbers are 51 and 39.

Therefore, the correct option is:
- 39 and 51