Solve a system of equations using any method: word problems

Model word problems with systems and choose an efficient solving method.

Lesson 7

Concept

Define variables from context, write two equations, choose graphing/substitution/elimination, then interpret solution units.

Adult tickets cost $12, student tickets cost $8. 40 tickets sold for $400. Find each quantity.

Best first step in system word problems is:

Choose random numbers

Define variables with units

Graph immediately

Eliminate constants only

How do you verify a context solution?

Substitute and check units/constraints

Only check one equation

Round heavily

Skip interpretation

These steps are out of order — can you fix them?

1.Solve system with chosen method

2.Write equations from constraints

3.Define variables

4.Interpret and verify

What makes one method “better” for a given word problem?