Answer:
Let b be the number of branches that the shrub will have after m months, since the shrub has an initial amount of 12 branches and the shrub grows 4 new branches every month, then we can set the following equation:
[tex]b=4m+12.[/tex]Evaluating the above equation at m=7 we get:
[tex]b=4\cdot7+12.[/tex]Simplifying the above result we get that the shrub will have
[tex]40[/tex]branches after 7 months.