1.75*7分之6+14分之3*1又4分之3+1又4分之3 遞等式計算,

1.75*7分之6+14分之3*1又4分之3+1又4分之3 遞等式計算,


1.75*7分之6+14分之3*1又4分之3+1又4分之3
=1又4分之3*7分之6+14分之3*1又4分之3+1又4分之3
=1又4分之3(7分之6+14分之3+1)
=4分之7×(14分之12+14分之3+14分之14)
=4分之7×14分之29
=8分之29



(4x+2)/x+(4x-22)/(x-5)=(x-6)/(x-4)+(7x+9)/(x+1)


(4X+2)/X+【4(X-5)-2】/(X-5)=【(X-4)-2】/(X-4)+【7(X+1)+2】/(X+1)
4+2/X+4-2/(X-5)=1-2/(X-4)+7+2/(X+1)
8+2/X-2/(X-5)=8+2/(X+1)-2/(X-4)
2/X-2/(X+1)= 2/(X-5)-2/(X-4)
1/X-1/(X+1)=1/(X-5)-1/(X-4)
1/【X(X+1)】=1/【(X-5)(X-4)】
20-10X=0
X=2



已知關於x的三次多項式除以x²;-1,餘式是4x+4,除以x²;-4時,餘式是7x+13.
求這個三次多項式,並因式分解


設多項式除以x^2-1的商為ax+b【∵多項式為三次式,除以二次式以後商只能是一次式】;除以x^2-4的商為cx+d
則(x^2-4)(cx+d)+7x+13=(ax+b)(x^2-1)+4x+4
=> cx^3-4cx+dx^2-4d+7x+13=ax^3+bx^2-ax-b+4x+4
=> cx^3+dx^2+(7-4c)x+(13-4d)=ax^3+bx^2+(4-a)x+(4-b)
=> c=a;d=b;7-4c=4-a;13-4d=4-b
=> a=c=1,b=d=3
所以,這個三次多項式為x^3+3x^2+3x+1因式分解,原式=(x+1)^3



4等於?要簡便運算


=2/5×1/10 +9/10×2/5=2/5×(1/10+9/10)=2/5×1=2/5