Aplumber charges $30 per hour and $42 for each hour of overtime. for a job, the plumber works 3 regular hours, h overtime hours, and charges $195 for new parts. the total amount of the bill for the job is $390. write and solve an equation to find the number of overtime hours the plumber worked.

You dug a hole that was 8 feet deep. after taking a short break, you dug down 3 more feet in the same hole. when finished digging, a tractor accidentally filled the hole with 4 feet of dirt. how deep is your hole now?

What are the solutions for the following system? -2x^2+y=-5 y=-3x^2+5

Stu and ambrose are working together on a study of whether diet is related to students' mental health. first, they randomly select 10 students from the student center and 10 students from the office of counseling and psychological services. then, they ask students to rate their diet in terms of healthiness on a scale of 1-100 before completing a 20-item mental health survey. a) name one of the constructs being studied b) how was the construct you named above operationally defined in this experiment? e) was the variable you described above their independent variable, their dependent variable, or a controlled variable? d) what is a confounding variable? what is a potential confound in this study?