Answer:

And on this case we can use the product rule for a derivate given by:

Where
and
And replacing we have this:

Step-by-step explanation:
We assume that the function of interest is:

And on this case we can use the product rule for a derivate given by:

Where
and
And replacing we have this:

A) i think is the correct answer
6+7+8+9+10=40 ********************
2x + y = 7
substitute
2x + (x+1) =7
combine like terms
3x+1 =7
subtract 1 from each side
3x =6
divide by 3
x=2
y = x+1
y =2+1
y=3
Answer: x=2, y=3