计算下列各题(要写出必要的演算步骤.)

1个回答

  • (1)(﹣4a 5b 3 2÷(8a 2b 3)÷(﹣53a 2),

    =16a 10b 6÷(8a 2b 3)÷(﹣53a 2),

    =2a 8b 3?(﹣53a 2),

    =﹣106a 10b 3

    (2)(x+2) 2﹣(x+3)(x﹣3),

    =(x 2+4x+4)﹣(x 2﹣9),

    =x 2+4x+4﹣x 2+9,

    =4x+13;

    (3)[(2x+1)(4x+2)﹣2]÷(﹣8x),

    =(8x 2+8x+2﹣2)÷(﹣8x),

    =(8x 2+8x)÷(﹣8x),

    =﹣x﹣1;

    (4)[(2x﹣y) 2+(2x+y)(2x﹣y)+8xy]÷2x,

    =(4x 2﹣4xy+y 2+4x 2﹣y 2+8xy)÷2x,

    =(8x 2+4xy)÷2x,

    =4x+2y,

    当x=﹣3,y=2时,原式=4×(﹣3)+2×2=8.