Question

A student was asked to solve 8x^2−28x=0
by factoring out the GCF.

At what step did the student first make an error?

Given: 8x^2−28x=0


Step 1: 4x(2x−7)=0


Step 2: 4x=0 and 2x−7=0


Step 3: x=0 and x=14


(1 point)

Step 1

Step 2

Step 3

Answer 1

Step 3.

Reason: From 2x − 7 = 0 we get 2x = 7 so x = 7/2 (not 14). The correct solutions are x = 0 and x = 7/2.