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Aidan has four cards with +, –, ×, ÷ printed on them. He inserts them between the five numbers 5, 4, 3, 2 and 1 to form the expression 5 + 4 × 3 – 2 ÷ 1, which has the value 15. Emma says: "Aidan put the operation cards in the order +, ×, –, ÷. If I place the operation cards in a different order between the numbers 5, 4, 3, 2, 1, I can make the value equal to 19." In what order did Emma place the four operations?

1 Answer

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9514 1404 393

Answer:

5 × 4 - 3 + 2 ÷ 1

Explanation:

We assume no parentheses are allowed. This expression evaluates to 19:

5 × 4 - 3 + 2 ÷ 1

= 20 -3 + 2 . . . . . . . multiplication and division are evaluated first

= 17 +2

= 19

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