What is the general form of the equation for the given circle centered at o(0, 0)?

When using the linear combination metho e linear combination method to solve a system of linear equations, the four options are:

The customer price index(cpi), which measures the cost of a typical package of customer goods, was 208.8 in 2011 and 244.1 in 2016.let x=11 corresponding to the year 2011 an estimate to cpi into 2013 and 2014. assume that the data can be modeled by a straight line and the trend to continue idenfinitely. use data points to find such a line and then estimate the requested quantities

Which of the following is best modeled using a linear equation y=ax+b, where a is less than 0?