You spend $20 total on tubes of paint and disposable brushes for an art project. tubes of paint cost $4.00 each and paintbrushes cost $0.50 each. you purchase twice as many brushes as tubes of paint. how many brushes and tubes of paint do you purchase?

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

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

36x2 + 49y2 = 1,764 the foci are located at: a) (-√13, 0) and (√13,0) b) (0, -√13) and (0,√13) c) (-1, 0) and (1, 0)