My last question i need to do on my : d would be appreciated!

val says that the model below represents the equation -2x+7 = 3x+(-4)
tia says that the model represents the equation 7-2x = (-4)+3x

who is correct, val or tia?

a: only val is correct.
b: only tia is correct.
c: both val and tia are correct.
d: neither val nor tia is correct.

The biologist has a second culture to examine. she knows that the population of the culture doubles every 15 minutes. after 1 hour and 15 minutes, her assistant found that 80,000 bacteria were present. a) what was the size of the initial population? b) predict the size of the culture at t=3 hours. what was the size of the population at 40 minutes? explain and justify your answers. c) create a graph of the population as a function of time. find an equation that can be used to predict the size of the population at any time t. d) examine the rate at which the bacteria culture is growing. how fast is the culture growing after 1 hour? after 1.5 hours? after 2 hours? use a time interval of h = 0.01 hours to estimate these rates. interpret these rates in terms of the context of the problem situation. how do these three rates compare?