alright so i have a problem with integrating the differential equation

dM/dt = 100 - kM

i have to separate the variables and then integrate the diffrerential equation to get an equation for M in terms of t. For the initial condition, M=0 when t=0

just for reference
my book is

CALCULUS
concepts and applications
2nd ed
key curriculum press

and the problem is in page 329 CH7 sec 3 Problem #1 c

any help will be greatly appreciated, thnx