Question

5a-[a的2次方+(5a的2次方-3a)-6(a的2次方-a)],其中a=1/2 化简求值

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Answer 1

5a-[a^2+(5a^2-3a)-6(a^2-a)]
=5a-(a^2+5a^2-3a-6a^2+6a)
=5a-a^2-5a^2+3a+6a^2-6a
=2a
=2×1/2
=1