There are going to be presentations at a school. if 30 people can fit in a room, how many rooms are necessary if there are a total of 40 people going to the presentations? rooms

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer

Jabari is power washing houses for a summer job. for every job, he charges an initial fee plus $30 for each hour of work. his total fee for a 4 -hour job, for instance, is $170 . jabari's total fee,f, for a single job is a function of the number,t, of hours it takes him to complete the job. write the function's formula.

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*