初一数学若12的x次方=3
初一数学:若12的x次方=3,12的y次方=2,求8的(1-2x/1-x+y)次方.
若12的x次方=3,12的y次方=2,求8的(1-2x/1-x+y)次方. 12^x=3,12^y=2,...12^(2y)=4,.....12^(x+2y)=12,....x+2y=1, .......1-x=2y,1-x+y=3y.1-2y=x 12^x=(2^2*3)^x=2^(2x)*3^y=3......2^(2x)*3^(y-1)=1 12^y=2^(2y)*3^y=2................2^(2y-1)*3^y)=1 ....2^(2x)*3^(y-1)=2^(2y-1)*3^y) ....2^[2x-(2y-1)]=3^[y-(y-1)]=3 ....2^[2x-2y+1]=3=2^x...2^(2y)=6
4/3 采用对数比较方便
问:数学题目(-3)2002次方+(-32003次方所得结果为?
答:(-3)^2002+(-3)^2003 =(-3)^2002*(1-3) =-2*3^2002详情>>
答:详情>>