Redirecting you to https://www.khanacademy.org/math/7th-grade-illustrative-math/unit-5-rational-number-arithmetic/lesson-13-expressions-with-rational-numbers/e/integer-addition-and-subtraction-with-substitutionhttps://www.khanacademy.org/math/7th-grade-illustrative-math/unit-5-rational-number-arithmetic/lesson-13-expressions-with-rational-numbers/e/integer-addition-and-subtraction-with-substitution