Solving an equation

Solve the equation 6x + 2 = 16 in as many ways as you can.

Approaches

What's a solution?

response: remind of earlier definition: a number you substitute for x to get a true statement. For example, is 2 a solution?

Guess and check.

There's no solution.

response: Why not? Are there numbers besides integers?

Undoing; if x was multipled by 6 and then 2 was added to get 16, to get back to x you subtract 2 and divide by 6.

Arrow diagrams

Balancing the equation

Graphing y = 6x + 2 on calculator, tracing to see where y-value is 16 or looking at table.

Graphing y = 6x + 2 and y = 16 on calculator, tracing to find intersection point.

Your experience

Have you used this problem with a class and seen approaches other than(or more specific than) those mentioned above? Or do you have other comments or criticisms or stories? If so, please tell us!

Last updated 30 November, 2004