What you’ll learn
Add positive and negative rational numbers.
Key idea
Common-denominator addition combines signed numerators; unlike subtraction, it does not negate the second input.
An addend keeps its own sign; negating the second input changes addition, while missing addend undoes the known addition.
Worked example
Enter the exact value or ordered values in the format requested below.
Add (-9/2)+(-4/3). Enter the exact rational number.
- Keep both signed operands: (-9/2)+(-4/3).
- A common denominator and signed numerators give -35/6; verify -35/6-(-9/2)=-4/3.
Answer: -35/6
Quick Check
Evaluate a worked attempt at add positive and negative rational numbers, identify the first invalid step, and provide the correction.
For (-9/2)+(4/3), Step 1 rewrites addition as (-9/2)-(4/3)=-35/6, negating the second operand. Locate the first invalid step and correct the sum.