Final answer:
The expression equivalent to 5.9 - 3.8 is 3.8 - 5.9, which is option 3, due to the rules of subtraction where the order of subtraction affects the sign of the result.
Step-by-step explanation:
The expression equivalent to 5.9 - 3.8 is 3.8 - 5.9, which is option 3. When subtracting numbers, the order in which you subtract them affects the sign of the result. Following the rules of subtraction, you would change the sign of the number being subtracted and then add the numbers. In this case, you would first change the sign of 3.8 to negative when moving it to the front, resulting in -3.8 and then subtract 5.9 from it, ending up with the same absolute value but a negative sign since 5.9 is larger than 3.8.The expression equivalent to 5.9 - 3.8 is Option 3) 3.8 - 5.9.
When subtracting two numbers, we change the sign of the number being subtracted and then follow the addition rules. So, 5.9 - 3.8 becomes 5.9 + (-3.8). Now, we can add the numbers, which gives us 2.1. Therefore, the expression is equivalent to 2.1.