standard_description: Prove that, given a system of two equations in two variables, replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions.
problem_activity: Ellen and Mundi each want to write a pattern that is 10 numbers long.
Ellen writes 0 as her first number and adds 2 each time to get her next number.
Mundi writes 0 as his first number and adds 6 each time to get his next number.
Ellen’s pattern:
0
,
2
,
,
,
,
,
,
,
,
Mundi’s pattern:
0  ,
6
,
,
,
,
,
,
,
,
a.   Complete Ellen and Mundi’s patterns.
b.   How many times greater is Mundi’s fourth number than Ellen’s fourth number?  What about the seventh numbers? The tenth numbers?
c.   What pattern do you notice in Part (b)?  Why do you think that pattern exists?


aligns: no