Hongke Du, Xiyan Yao, Chunyuan Deng, Invertibility of Linear Combinations of Two Idempotents, Proceedings of the American Mathematical Society, Vol. 134, No. 5 (May, 2006), pp. 1451-1457 ...

And this is exactly what linear regression does. It finds a combination of features (columns in your table) and coefficients (numbers to multiply those columns by) that most closely match the ...

C. J. Park, The Distribution of Weighted Linear Combinations of Cell Frequency Counts: Two Samples from Continuous Distributions, Sankhyā: The Indian Journal of Statistics, Series A (1961-2002), Vol.