Question

10^x次方等于3 ,10^y次方等于4 求10^-y/2, 求10^3（X-Y),求10^-X+10^-Y

Answer 1

10^-x=10^x * 10^-1=3*(1/10)=3/10

10^-y=10^y * 10^-1=4*(1/10)=2/5

10^-x+10^-y=3/10+2/5=7/10

10^-y/2=10^-y * 10^1/2=2/5 * √10 =2√(2/5)