计算 ①m²-﹙m+2﹚﹙m-3﹚ ②﹙a-b﹚²+b(2a=b) ③﹙x-3y﹚(y+3x)-(x-3y)(3x-y)④﹙2x-y+3﹚(2x+y-3) 分解因式 ① ab³-4ab ② 3x²y+12xy²+12y³ ③ -3x²y³z+9x³y³z-6x四次方yz²
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![计算 ①m²-﹙m+2﹚﹙m-3﹚ ②﹙a-b﹚²+b(2a=b) ③﹙x-3y﹚(y+3x)-(x-3y)(3x-y)④﹙2x-y+3﹚(2x+y-3) 分解因式 ① ab³-4ab ② 3x²y+12xy²+12y³ ③ -3x²y³z+9x³y³z-6x四次方yz²](/uploads/image/z/2538598-22-8.jpg?t=%E8%AE%A1%E7%AE%97+%E2%91%A0m%26%23178%3B-%EF%B9%99m%2B2%EF%B9%9A%EF%B9%99m-3%EF%B9%9A+%E2%91%A1%EF%B9%99a-b%EF%B9%9A%26%23178%3B%2Bb%282a%3Db%29+%E2%91%A2%EF%B9%99x-3y%EF%B9%9A%28y%2B3x%29-%28x-3y%29%EF%BC%883x-y%EF%BC%89%E2%91%A3%EF%B9%992x-y%2B3%EF%B9%9A%282x%2By-3%29+%E5%88%86%E8%A7%A3%E5%9B%A0%E5%BC%8F+%E2%91%A0+ab%26%23179%3B-4ab+%E2%91%A1+3x%26%23178%3By%2B12xy%26%23178%3B%2B12y%26%23179%3B+%E2%91%A2+-3x%26%23178%3By%26%23179%3Bz%2B9x%26%23179%3By%26%23179%3Bz-6x%E5%9B%9B%E6%AC%A1%E6%96%B9yz%26%23178%3B)
计算 ①m²-﹙m+2﹚﹙m-3﹚ ②﹙a-b﹚²+b(2a=b) ③﹙x-3y﹚(y+3x)-(x-3y)(3x-y)④﹙2x-y+3﹚(2x+y-3) 分解因式 ① ab³-4ab ② 3x²y+12xy²+12y³ ③ -3x²y³z+9x³y³z-6x四次方yz²
计算 ①m²-﹙m+2﹚﹙m-3﹚ ②﹙a-b﹚²+b(2a=b) ③﹙x-3y﹚(y+3x)-(x-3y)(3x-y)
④﹙2x-y+3﹚(2x+y-3) 分解因式 ① ab³-4ab ② 3x²y+12xy²+12y³ ③ -3x²y³z+9x³y³z-6x四次方yz² ④ ﹙x+2﹚(x-6)+16 ⑤(x+y)²-4x² ⑥x³-6x²+9x ⑦﹙ x² -2x)²+2(x²-2x)+1
化简求值 (-2a+5)(-5-2a)+(4-a)²-4(a+1)(a-3),其中 a=-3小明错误的把a=-3抄成了a=3但显示计算的结果是正确的,这是怎么回事吗?
计算 ①m²-﹙m+2﹚﹙m-3﹚ ②﹙a-b﹚²+b(2a=b) ③﹙x-3y﹚(y+3x)-(x-3y)(3x-y)④﹙2x-y+3﹚(2x+y-3) 分解因式 ① ab³-4ab ② 3x²y+12xy²+12y³ ③ -3x²y³z+9x³y³z-6x四次方yz²
(-2a+5)(-5-2a)+(4-a)²-4(a+1)(a-3)
=-(5-2a)(5+2a)+16-8a+a²-4a²+12a-4a+12
=-【5²-(2a)²]+16-8a+a²-4a²+12a-4a+12
=-25+4a²+16-8a+a²-4a²+12a-4a+12
=a²+3
∵a=-3或a=3时
a²都等于9
∴a²+3=9+3=12
∴计算是对的
(-2a+5)(-5-2a)+(4-a)²-4(a+1)(a-3)
=-(5-2a)(5+2a)+16-8a+a²-4a²+12a-4a+12
=-【5²-(2a)²]+16-8a+a²-4a²+12a-4a+12
=-25+4a²+16-8a+a²-4a²+12a-4a+1...
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(-2a+5)(-5-2a)+(4-a)²-4(a+1)(a-3)
=-(5-2a)(5+2a)+16-8a+a²-4a²+12a-4a+12
=-【5²-(2a)²]+16-8a+a²-4a²+12a-4a+12
=-25+4a²+16-8a+a²-4a²+12a-4a+12
=a²+3
∵a=-3或a=3时
a²都等于9
∴a²+3=9+3=12
∴它所显示的计算结果是正确的
收起
当然不能!