What is the value of the expression 3a² − 2ab when a = −2 and b = 5?

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Question

What is the value of the expression 3a² − 2ab when a = −2 and b = 5?

Accepted Answer

32 — Award 1 mark for correct substitution and evaluation: 3(−2)² − 2(−2)(5) = 3(4) − (−20) = 12 + 20 = 32. B is incorrect — results from calculating 3(4) − 2(5) = 2, ignoring signs. C is incorrect — results from incorrect handling of (−2)² as −4. D is incorrect — results from subtracting instead of adding 20.

Answer

−32

Answer

−8

Answer

32

Answer

2

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