Contact us
Choose a category below so we can get back to you as quickly as possible.
x²+5x-990=0 可得:x²+5x=990x³+6x²-985x+1017=(x³+5x²)+x²-985x+1017=x(x²+5x)+x²-985x+1017 將x²+5x 用990代替得:=990x+x²-985x+1017 將990x與-985x合併...
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.