Example 3a.
in the Warm Ups, from the last page and just below, is a SYSTEM of linear equations presented as a SINGLE
sophisticated linear equation. To solve it, substitution is employed. Below, examine it now from a linear
system perspective.
Solve Linear Systems by Substitution.
 
1st:  Use two display areas sidebyside for representing
an equation. (These will later be moved to the top away from the user.) 
2nd:  Pick one equation to solve for one variable. Take the
easy equation and the easy variable or use another method. 
3rd:  Solve the equation for the variable of choice. 
4th:  Move the solved equation in the sidebyside display
areas to the top, away from the user, and use two additional sidebyside display areas for the other
equation, placing them on the bottom close to the user. 


5th:  Represent the other equation IN THE STORAGE AREAS
ABOVE THE DISPLAY AREAS. 
6th:  In the bottom display areas,
SUBSTITUTE, replace, each of the solved variable tiles with the expression found in the third step and
duplicate exactly all other tiles. 
7th:  Solve the equation from the step six. 
8th:  Move the easy equation to the top storage areas above
the display areas. 


9th:  In the top display areas,
SUBSTITUTE, replace, each of the other variable tiles with the new value from step 7 and duplicate exactly
all other tiles. 
10th:  Solve the easy equation. 
11th:  State the solution and include values for both
variables. 
