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Re: If –4 ≤ a ≤ 9, and –3 ≤ b ≤ 2, then what is the greatest
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20 Mar 2018, 15:28
Explanation
You are being asked to subtract the a and b terms. Be careful that you don’t just combine the largest value of a with the largest value of b to get a – b = 9 – 2 = 7, the wrong
answer.
When you combine inequalities, you have to make four calculations to check the four possibilities.
Subtract the smallest values of a and b: –4 – (–3) = –1. Subtract the largest values of a and b: 9 – 2 = 7.
Subtract the smallest value of a and the largest value of b: –4 – 2 = 6.
Subtract the largest value of a and the smallest value of b: 9 – (–3) = 12. Of the four possible values above, the greatest possible value is 12.