Question

with quadratic equations how do I know when to add or subtract!

Answer 1

Where are you asking about adding or subtracting?

Answer 2

well with \[1\pm \sqrt{1^2 -4(1)(-4)} \] would this be a situation to add since a neg 4 times a neg 4 is a positive 16

Answer 3

Yes. You would add.

Answer 4

okay beacuse in my math book there is a similar one and they subtracted. it was \[-2 \pm \sqrt{2^2 - 4(5)(-2)} \over 2(5)\]

Answer 5

Well, you add inside the square root for both cases because you're multiplying two negative numbers together.

Answer 6

right but the answer in the book depends on it being subtracted. So is the book just plain wrong?