1/4(x-3)+1/5(x-4)+1/6(x-5)+1/7(x-6)=-4解方程.能否简便?注意,

Question

1/4(x-3)+1/5(x-4)+1/6(x-5)+1/7(x-6)=-4解方程.能否简便?注意,

Answer 1

1/4x+1/5x+1/6x+1/7x-3/4-4/5-5/6-6/7=-4 全部乘出来；
(1/4+1/5+1/6+1/7)x-(4-1/4-1/5-1/6-1/7)=-4 带x项合并,3/4转化成1-1/4,以此类推；
(1/4+1/5+1/6+1/7)x-4+(1/4+1/5+1/6+1/7)=-4 把-4提出来,其他化成加；
(1/4+1/5+1/6+1/7)(x+1)=0 合并同类项；
x+1=0
x=-1