x(X-1)/2=45怎么解
问题描述:
x(X-1)/2=45怎么解
答
x²-x=90
x²-x-90=0
(x-10)(x+9)=0
x=10,x=-9
x(X-1)/2=45怎么解
x²-x=90
x²-x-90=0
(x-10)(x+9)=0
x=10,x=-9