Question

Ryan is trying to determine whether 2.7x – 5.9 is equivalent to 2.8x – 5.9. To test this, he substitutes 0 for x into both expressions. Explain why this will not give him the correct answer.

Answer 1

See below.

Explanation:

It's because any number multiplied by 0 equals 0. We could put any 2 numbers other than 2.7 and 2.8 yet still get both sides of the equation = - 5.9 but the 2 sides are obviously not equal.

To do the test correctly he can use any number except 0.