In order to subtract these two numbers, we will first need to take out a common factor of negative one.

We can then subtract the terms.

Borrow a one from the tens digit to subtract the ones digits. The tens digit of 981 becomes a 7.

Borrow a one from the hundreds place to subtract the tens digits. The hundreds place of 981 becomes an eight.

Subtract the tens digits.

Subtract the hundreds digits.

The expression becomes:

The answer is:

Write an expression to set up the problem.

Add the ones digits.

The carryover is tens place, which is two.

Add the tens digits.

The carryover is three.

Add the hundreds places with the carryover. The two digit numbers will have zero as the hundreds places.

Combine the ones digits from each calculation.

The answer is:

Add the ones digits.

Add the tens digits.

Add the hundreds digits with the carryover, 1.

Add the thousands digits with the carryover.

The answer is:

Borrow a one from the tens digit of 915 in order to subtract the ones digits. The tens digit of 915 becomes zero.

Borrow a one from the hundreds digit of 915 in order to subtract the tens digits. The hundreds digit becomes an eight.

Subtract the hundreds digits.

Combine the numbers.

The answer is:

Add the ones digits.

Add the tens digits with the carryover.

Add the hundreds digits with the carryover.

Combine the digits together to determine the answer.

The answer is:

Add the ones digits.

The tens digit is the carryover.

Add the tens places with the carryover.

Add the hundreds places with the new carryover.

Add the thousands places with the new carryover.

Combine all the ones digits.

The answer is:

Add the ones digits.

The carryover is the tens digit of this number.

Add the tens digits with the carryover.

The carryover is the tens digit of this number.

Add the hundreds digits with the carryover.

Combine the digits.

The answer is:

Add the ones digits.

Add the tens digits.

Add the hundreds digits with the tens digit as the carryover.

Add the thousands digit with the carryover, 2.

Combine this number with the ones digits of the previous numbers.

The answer is:

To solve this system of equations by elimination you first need to multiply the first equation by -2. This will allow the y terms to cancel when equation 1 and equation 2 are adding together.

Now solve for x.

Substitute the x value into the orginial equation and solve for y.

Add the ones digits.

The carryover is the tens place.

Add the tens place with the carryover.

Add the hundreds place with the carryover of this calculation.

Combine this number with the ones digits of the previous calculations.

The answer is: