Help :) please y’all question 3 and 4

What is the multiplicative rate of change of the exponential function shown on the graph?

Sunday: 1 1 2 monday: 1 tuesday: 2 1 2 wednesday: 1 3 4 thursday: 2 friday: 1 1 2 saturday: 2 jenna is a swimmer and trains every day. the schedule shown outlines the number of hours she trains each day. what is the total number of hours that jenna trains during the week?

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form