Question

0.96X=60X0.8+(X-60)X1.2 求解

Answer 1

0.96x=48+1.2x-72
1.2x-0.96x=72-48
0.24x=24
x=24÷0.24
x=100

Answer 2

奇函数则f(0)=0
1-4/(2+a)=0
a=2

f(x)=1-4/(2*2^x+2)=1-2/(2^x+1)
2^x>0
2^x+1>1
0<1/(2^x+1)<1
-2<-2/(2^x+1)<0
4-2<4-2/(2^x+1)<4+0
值域(2,4)