What is 15x-x3+3 in standard for and what would the name of it be?

Using d, e, and f as values on a triangle and d being 60 degrees, what is the value of e and f if d is 60 degrees? also, what do you notice about the values of e and f?

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

Which of these equations, when solved, gives a different value of x than the other three? a9.1 = -0.2x + 10 b10 = 9.1 + 0.2x c10 – 0.2x = 9.1 d9.1 – 10 = 0.2x