1计算(X-0.5)(X+0.5)(XX+0.25)____________
4个回答

(x-0.5)(x+0.5)(x^2+0.25

=(x^2-0.25)(x^2+0.25)

=x^4-0.0625

(a^2+ma+1)(a-2)

=a^3+(m-2)a+(1-2m)a-2

有a的一次项

所以1-2m=0

m=1/2

x+y=10

xy=24

(x+y)^2=10^2

x^2+2xy+y^2=100

x^2+2*24+y^2=100

x^2+y^2=100-48=52