compute

-2.351-4.87=
17.63+(-28.862)=

-2.351 - 4.87 = -7.221

17.63 + (-28.862) = -11.232

To compute these two calculations step-by-step, we will use the basic operations of addition and subtraction.

1. -2.351 - 4.87:

To subtract -4.87 from -2.351, we line up the decimal points and subtract the numbers as if they were whole numbers:

-2.351
- 4.870
_______
-7.221

Therefore, -2.351 - 4.87 = -7.221.

2. 17.63 + (-28.862):

To add 17.63 and -28.862, we simply add the numbers together:

17.630
+ (-28.862)
__________
-11.232

Therefore, 17.63 + (-28.862) = -11.232.

To compute these equations, you simply need to perform the indicated arithmetic operations.

For the first equation:
-2.351 - 4.87

You need to subtract 4.87 from -2.351. To do this, you align the decimal point and subtract each digit in the corresponding place value:

-2.351
- 4.87
__________
-7.221

So, -2.351 - 4.87 equals -7.221.

For the second equation:
17.63 + (-28.862)

Here, you need to add 17.63 and -28.862. Since there is a negative sign in front of -28.862, you can think of it as subtracting 28.862 from 17.63:

17.63
- 28.862
__________
-11.232

Thus, 17.63 + (-28.862) equals -11.232.