化简 2(6+sqrt(21))

解答

化简

2 (6 + 21)

12 + 221

十进制

21.16515 \dots

求解步骤

2 (6 + 21)

使用分配律:

a (b + c) = ab + a c

2 (6 + 21) = 2 \cdot 6 + 221

= 2 \cdot 6 + 221

数字相乘:

2 \cdot 6 = 12

= 12 + 221

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