Respuesta :

Яɒwɿ
a. 2^x=15
    xlog2=log15
    x=log15/log2
    x=3.907

b. 4^x=81
    xlog4=log81
    x=log81/log4
    x=3.170

c. 12^x=211
    xlog12=log211
    x=log211/log12
    x=2.154

d. 7^x=289
    xlog7=log289
    x=log289/log7
    x=2.912


Hope I didn't mess up for your sake.