Help a girl outtt☹️☹️ if i dont do these i may fail the whole yearr

Use the elimination method to find the solution to the system of equations. 2x - 3y = -9 -x + 3y = 6

News cameras take an overhead picture of a crowd at an outdoor event journalist then count the total number of people in the picture and use the sample of estimate the total number of people in the crowd this process is an example of

Select all of the quadrants that the parabola whose equation is y=√x-4 (principal square root) occupies. i ii iii iv