Three students were given the expression shown and were asked to take a common factor out of two of the terms. 4-9x+21

Step-by-step explanation:

Expression given → 4 - 9x + 21

Chang's expression → 4 - 3(3x + 7)

Chang's expression is incorrect because the correct expression is [4 - 3(3x - 7)]

Benjamin's expression → 4 + 3(3x + 7)

Benjamin's expression is incorrect because the correct expression is [4 - 3(3x - 7)]

Habib's expression → 4 + 12x

Habib's expression is incorrect because the correct expression is [4 - 3(3x - 7)]

Correct expression → [4 - 3(3x - 7)]

set each factor equal to 0

4x-3 = 0

2x-1 = 0

solve for x.

4x-3=0

4x=3

x= 3/4

solve for x. 

2x-1= 0

2x= 1

x= 1/2

eventually after a few more steps, your answer should be 1/2 is less than or equal to x and 3/4 is greater than or equal to x