计算:[﹙x/2+3y﹚²﹣﹙y/2﹢x﹚²+﹙3x-y/2﹚²-﹙x/2+3y﹚﹙3y-x2-]÷x/2
问题描述:
计算:[﹙x/2+3y﹚²﹣﹙y/2﹢x﹚²+﹙3x-y/2﹚²-﹙x/2+3y﹚﹙3y-x2-]÷x/2
答
[﹙x/2+3y﹚²﹣﹙y/2﹢x﹚²+﹙3x-y/2﹚²-﹙x/2+3y﹚﹙3y-x2)]÷x/2
(中括号内,第一、四项提取(X/2+3Y),第二、三项用平方差公式)
=[(X/2+3Y)(X/2+3Y-3Y+X/2)+(3X-Y/2+Y/2+X)(3X-Y/2-Y/2-X)]*2/X
=[X^2/2+3XY+8X^2-4XY]*2/X
=[17/2X^2-XY]*2/X
=17X-2Y.