A First Course in Linear Algebra · Problem SSLE.M30

Systems of Linear Equations — Robert Beezer

Mathematics — Linear Algebra · solving-systems-of-linear-equations

Problem

This problem appears in a middle-school mathematics textbook: Together Dan and Diane have \

20. Together Diane and Donna have

15. How much do the three of them have in total? (Transition Mathematics, Second Edition, Scott Foresman Addison Wesley, 1998. Problem 5--1.19.)