课前预习答案
每一项;单项式;相加
课堂探究例1思路导引答案
1、6x3 y2; - 7x4y ;6x2y;- 7x3
2、0.3a2b;-(1/3)a3b2;- (1/6)a4b3; -3/5;(2/3)ab;(1/3)a2b2
解:(1)原式=6x3y2÷(xy) - 7x4y÷(x-y) =6x2y-7x3
(2)原式=0.3a2b÷(-0.5a2b)-(1/3)a3b2÷(-0.5a2b)-(1/6)a4b3÷(-0.5a2b) =-3/5+(2/3)ab+÷(1/3)a2b2
课堂探究例1变式训练1-1答案
C
课堂探究例1变式训练1-2答案
(2/3)x3+2x4-3x2
课堂探究例1变式训练1-3答案
解:(1)原式=4a2 -2a+1;
(2)原式=(4a⁴b⁷+3a3b⁸ -4a2b⁶)÷4a2b⁶
=a2b+(3/4)ab2-1
课堂探究例2思路导引答案
2x2-2xy;1/2(x-y) ;2.25
解:[(x-y)2+(x+y)(x-y)]÷(4x)
=[(x2 -2xy+y2)+x2 -y2]+(4x)
=(2x2 -2xy)÷(4x)
=1/2(x-y)
当x=3,y=-1.5时,原式=1/2[3-(-1.5)]=2.25
课堂探究例2变式训练2-1答案
D