Question

化简求直 当X=--3时,求X(X-4)(X+4)-(X+3)(X的平方-6X+9)+5X的立方Y的平方除X的平方Y的平

Answer 1

X(X-4)(X+4)-(X+3)(X^-6X+9)+5X^3Y^2/(X^2Y^2)

X=-3所以(X+3)(X^-6X+9)=0

所以原式=X(X^2-16)+5X[X^2Y^2/(X^2Y^2)]

=X(X^2-16)+5X

=X^3-16X+5X

=X^3-11X

X=-3

原式=6