Example

Translating 'the difference of 1313 and −21-21' and 'subtract 2424 from −19-19'

Translate each English phrase into an algebraic expression and simplify:

(a) "The difference of 1313 and −21-21": The keyword difference signals subtraction, and the prepositions of and and identify the two quantities in their given order. Translate as 13−(−21)13 - (-21). Since subtracting a negative is equivalent to adding a positive: 13+21=3413 + 21 = 34.

(b) "Subtract 2424 from −19-19": The phrase "subtract bb from aa" always means a−ba - b — the number that follows from is written first in the expression. Translate as −19−24-19 - 24. Both terms are negative, so add the absolute values and keep the negative sign: −19−24=−43-19 - 24 = -43.

The order of the operands is critical. With difference of, the first quantity named is written first (a−ba - b). With subtract from, the quantity after from is written first (a−ba - b), reversing the reading order. Mixing up the order is a common error.

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Updated 2026-04-21

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