Question

(M的平方-M)/M+2除以A＝（M的平方-M的三次方）/4-M的平方,则A＝多少?

Answer 1

(M^2-M)/(M+2/A)=(M^2-M^3)/(4-M^2)

M(M-1)/(M+2/A)=M^2(1-M)/(4-M^2)

1/(M+2/A)=-M/(4-M^2)

-M(M+2/A)=(4-M^2)

-M^2-2M/A=4-M^2

-2M/A=4

A=-M/2