男生有a人,比女生人数的2倍少5人,女生有多少人 学校有男生a人女生人数比男生人数的2倍少b人2a减b表示多少...
\u67d0\u73ed\u7537\u751f\u6709a\u4eba\u7537\u751f\u4eba\u6570\u6bd4\u5973\u751f\u76841.2\u500d\u5c11\u516b\u4eba\u5168\u73ed\u6709\u591a\u5c11\u4eba,\u5f53a\u7b49\u4e8e16,\u5168\u73ed\u6709\u591a\uff1f\u7531\u9898\u610f\u53ef\u77e5\uff0c\u5973\u751f\u4eba\u6570\u4e3a(a+8)/1.2\uff0c
\u6240\u4ee5\u5168\u73ed\u4eba\u6570=(a+8)/1.2+a,
\u5f53a=16\u65f6\uff0c\u5168\u73ed\u4eba\u6570=\uff0816+8\uff09/1.2+16=30\u4eba
\u770b\u56fe\u5427
(a+5)/2
绛旓細2a-7
绛旓細璁濂崇敓鏈墄浜猴紝2x-b=a,x=(a+b)/2
绛旓細(a+7)/2 a涓嶇煡閬擄紝鍙兘寰楀嚭濂崇敓浜烘暟鐨浠f暟
绛旓細濂崇敓浜烘暟鏄疉+7/2,骞寸骇鍏辨湁3A+7/2
绛旓細瑙o細锛1锛鐢风敓鏈塧浜猴紝濂崇敓姣鐢风敓鐨2鍊嶅皯25浜猴紝鍒欏コ鐢熶汉鏁颁负锛氾紙2a锕25锛変汉锛涳紙2锛鐢风敓鏈塧浜猴紝濂崇敓浜烘暟涓猴細锛2a锕25锛変汉锛屽垯鐢风敓姣斿コ鐢澶氱殑浜烘暟涓猴細a锕o紙2a锕25锛=锛25锕锛変汉锛涳紙3锛夊叏鐝汉鏁颁负锛歛+2a锕25=锛3a锕25锛変汉锛庣瓟锛氬垵涓锛1锛夌彮锛屽コ鐢熸湁锛2a锕25锛変汉锛岀敺鐢熸瘮濂崇敓澶氾紙25锕...
绛旓細鐢风敓浜烘暟鏄:2a锛20 鐢风敓姣斿コ鐢澶=2a锛20锛峚 =a锛20
绛旓細鐢风敓鏈 2a-20浜 ---
绛旓細鍙傚姞鏍¤繍鍔ㄤ細鐨勫鐢熸绘暟涓310浜恒鐢风敓浜烘暟鏄コ鐢鐨勪袱鍊鍐嶅噺鍘2浜恒傝濂崇敓浜烘暟涓篨銆傛牴鎹鐩俊鎭紝鎴戜滑鍙互寤虹珛浠ヤ笅鏂圭▼锛氱敺鐢熶汉鏁 = 2 * 濂崇敓浜烘暟 - 2 鐢风敓浜烘暟 + 濂崇敓浜烘暟 = 310 灏嗙涓涓柟绋嬩腑鐨勭敺鐢熶汉鏁颁唬鍏ョ浜屼釜鏂圭▼涓紝寰楀埌锛(2 * 濂崇敓浜烘暟 - 2) + 濂崇敓浜烘暟 = 310 3 * 濂崇敓浜烘暟 - ...
绛旓細1.2a-25 2.(-a)-25 3.3a-25 甯屾湜鑳藉府鍒颁綘锛屾垜鐜板湪鍒濅竴锛屾暟瀛︿笉澶ソ锛
绛旓細2a-b 鎶奱=16b=7甯﹀叆杩欎釜寮忓瓙涓 2脳16锛7=32-7=25鎵浠鐢风敓涓25浜猴紝鍏ㄧ彮鐨浜烘暟鏄32+25=57