来自毛乾霖的问题
{100-5(X-10)/2}*X=1360
{100-5(X-10)/2}*X=1360
1回答
2020-04-26 15:27
{100-5(X-10)/2}*X=1360
{100-5(X-10)/2}*X=1360
100x-5/2*(x^2-10x)=1360-5/2x^2+25x+100x=13605x^2-250x+2720=0x^2-50x+544=0x=(50±sqrt(Δ))/2(Δ=50^2-4*544=324)=(50±18)/2=34或16LZ这题是有技巧的,先拆括号,然后整理,按照X指数幂的降序排列,然后用求根公式...