问题
计算题
计算下列各题(要写出必要的演算步骤.)
(1)(﹣4a5b3)2÷(8a2b3)÷(﹣53a2);
(2)(x+2)2﹣(x+3)(x﹣3);
(3)[(2x+1)(4x+2)﹣2]÷(﹣8x);
(4)化简、求值:[(2x﹣y)2+(2x+y)(2x﹣y)+8xy]÷2x,其中x=﹣3,y=2.
答案
解:(1)(﹣4a5b3)2÷(8a2b3)÷(﹣53a2),
=16a10b6÷(8a2b3)÷(﹣53a2),
=2a8b3?(﹣53a2),
=﹣106a10b3;
(2)(x+2)2﹣(x+3)(x﹣3),
=(x2+4x+4)﹣(x2﹣9),
=x2+4x+4﹣x2+9,
=4x+13;
(3)[(2x+1)(4x+2)﹣2]÷(﹣8x),
=(8x2+8x+2﹣2)÷(﹣8x),
=(8x2+8x)÷(﹣8x),
=﹣x﹣1;
(4)[(2x﹣y)2+(2x+y)(2x﹣y)+8xy]÷2x,
=(4x2﹣4xy+y2+4x2﹣y2+8xy)÷2x,
=(8x2+4xy)÷2x,
=4x+2y,
当x=﹣3,y=2时,原式=4×(﹣3)+2×2=8.