The true statement is that Stephen's factored expression is incorrect.
Given
The expression is given as:
[tex]\rm x^2-10x+21[/tex]
Factorization involves splitting a function into factors.
Start by expanding the equation
[tex]\rm x^2-10x+21=0\\\\x^2-7x-3x+21=0[/tex]
Factorize the equation
[tex]\rm x^2-7x-3x+21=0\\\\x(x-7)-3(x-7)=0[/tex]
Factor out x - 7
[tex]\rm x(x-7)-3(x-7)=0\\\\(x-7)(x-3)=0[/tex]
Hence, the true statement is that Stephen's factored expression is incorrect.
Read more about factored expressions at:
brainly.com/question/11579257
