Answer:
[tex]c=2[/tex]
Step-by-step explanation:
Step 1
The first step is to simplify expand the the equation and collect like terms. This calculation is shown below,
[tex]g(x)=2\bigl(x^2+14x+7\bigr)-7(x+c)\\g(x)=2x^2+28x+14-7x-7c\\g(x)=2x^2+21x+14-7c\\g(x)=x(2x+21)+7(2-c).[/tex]
Step 2
The second step is to realize that that x woll divide g only if the constant term is 0.
[tex]7(2-c)=0\\\implies 2-c=0\\\implies 2=c.[/tex]
The value of c is 2