La grafica muestra la relación entre el tiempo en que un autobus recorre las distancias. ¿Cual es la razón de proporcionalidad? a) 120 km/h b) 90 km/h c) 60 km/h d) 40 km/h

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation:

i think the answer would be c

y-y1=m(x-x1)

y-1=1(x-8)