Problem: How do I do this? w2 - 18w - 40
I'm lost in Algebra. I've been doing Algebra one for 3 years now and I can't seem to understand. Can anyone help me?
Thank you, xoxo;
Assuming that w2 is actually w^2 (dangerous assumption).
w^2 - 18w - 40
(w - 20)(w + 2)
Next assumption: w^2 - 18w - 40 = 0
Taking that as the assumption, one or both factors
must equal zero.
w - 20 = 0
w = 20
w + 2 = 0
w = -2
Verify those values.
w^2 - 18w - 40 = 0
20^2 - 18(20) - 40 = 0
400 - 360 - 40 = 0
0 = 0
w^2 - 18w - 40 = 0
(-2)^2 - 18(-2) - 40 = 0
4 + 36 - 40 = 0
0 = 0