-   Let 138.009 + 341.981 - 146.305 = 123.6 + x   Then, x = (138.009 + 341.981) - (146.305 + 123.6) = 479.99 - 269.905 = 210.085.

To solve the given question, we need to use the basic arithmetic operations of addition and subtraction.

• Addition: In mathematics, addition is the process of combining two or more numbers or other mathematical objects to produce a sum. It is one of the four basic operations of arithmetic, the others being subtraction, multiplication and division.

• Subtraction: Subtraction is an arithmetic operation that represents the operation of removing objects from a collection. It is signified by the minus sign (-). For example, in the picture on the right, there are 5 − 2 apples—meaning 5 apples with 2 taken away, which is a total of 3 apples.

Now let us solve the given question:

138.009 + 341.981 - 146.305 = 123.6 + ?

Step 1: We need to solve the addition and subtraction expression first.

138.009 + 341.981 - 146.305 = 344.685

Step 2: Now we need to subtract 123.6 from the result obtained in Step 1.

344.685 - 123.6 = 221.085

Step 3: Now we need to add the numbers inside the brackets.

221.085 + (120.85) = 210.085

Therefore, the answer to the given question is Option D 210.085.

If you think the solution is wrong then please provide your own solution below in the comments section .