(b)
A polynomial has the form

± 
+ ....
the only expression fitting this description is : x² + 2x + 7
You need to substitute the number 6 into the function. The output would be 72, because when l(6) = 12(6), you would get l(6) = 72.
1. Negative
Explanation: A negative minus a positive will be a negative
2. Negative
Explanation: If you use your order of operations a negative multiplied by a negative will be positive but since BxB would be greater than A it would be negative for example 2-8 would equal -6
we have

Step 
Move the constants to the right side

Step 
Factor 3 out of the variable terms

Step 
Add
to both sides of the equation


Step 
Write the polynomial as a binomial squared

therefore
the answer is
Factor 3 out of the variable terms.