‘2’是平方 1. -2ac2/14a2bc 2. 4-a2/a2-2a 3. x2-16/2x+8 4.x2-16/8
1个回答

(1)

(-2ac2)/(14a2bc)

=-c/7ab

=-c/7ab

(2)

(4-a2)/(a2-2a)

=(22-a2)/a(a-2)

=(2+a)(2-a)/-a(2-a)

=2+a/-a

=-2+a/a

(3)

(x2-16)/2x+8

=(x2-42)/2(x+4)

=(x+4)(x-4)/2(x+4)

=x-4/2

4.

(x2-16)/8-2x,其中x=-2

(x2-16)/8-2x

=(x2-42)/2(4-x)

=(x+4)(x-4)/-2(x-4)

=x+4/-2

=-x+4/2

=--2+4/2

=-2/2

=-1