Solve by factoring: m^2+8m+7=0
Which answer is correct....(A. 8, 7),(B. -7, 1),(C. -7, -1), or (D. 7, 1)

Question

Solve by factoring: m^2+8m+7=0
Which answer is correct....(A. 8, 7),(B. -7, 1),(C. -7, -1), or (D. 7, 1)

anikay · Answer

Okay so we're factoring. do you know the easiest way to factor?

anikay · Answer

by completing the square.

anonymous · Answer

The square?

anikay · Answer

mmk, let me explain it's impossible to factor the expression you gave me, as it is.

anikay · Answer

so we mess with the equation a little and "complete to square" to enable factoring.

anikay · Answer

so what I'm saying is $$m^2+8m+7=0$$ cannot be factored
we must instead complete the square
$$m^2+8m+7+9=0+9$$

anonymous · Answer

Ah

anikay · Answer

so give it a try. see if you can do it from there.

anonymous · Answer

multiple choice supposes that one of the answers is correct to start with.  To save time on a test you can simply dbl chk the options to see what fits.  Otherwise, anikay's process is fine :)