化简-(2a+3b-4)+(a-2b+5)-(4a-7b-6)

解答

化简

- (2 a + 3 b - 4) + (a - 2 b + 5) - (4 a - 7 b - 6)

- 5 a + 2 b + 15

求解步骤

- (2 a + 3 b - 4) + (a - 2 b + 5) - (4 a - 7 b - 6)

使用法则:

a + (b + c) = a + b + c

- (2 a + 3 b - 4) + (a - 2 b + 5) = - (2 a + 3 b - 4) + a - 2 b + 5

= - (2 a + 3 b - 4) + a - 2 b + 5 - (4 a - 7 b - 6)

- (2 a + 3 b - 4) = - 2 a - 3 b + 4

- (4 a - 7 b - 6) = - 4 a + 7 b + 6

= - 2 a - 3 b + 4 + a - 2 b + 5 - 4 a + 7 b + 6

对同类项分组

= - 2 a + a - 4 a - 3 b - 2 b + 7 b + 4 + 5 + 6

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