Can someone tell me what’s the answer please ?!

Measures of the angle of r, 31 s (x+4) t (3x+9)

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

When i'm with my factor 5, my prodect is 20 .when i'm with my addend 6' my sum is 10.what number am i