I can't figure out the answers. For the last one, I think that the answer is D. 19.6ft but I don't know. Sorry. Please show work!

Guest Sep 12, 2018

#1**+1 **

-3x^2 + 2x - 3 = 0

a = -3 b = 2 c = -3

Using the Quadratic Formula

x = [ - b ±√ [ b^2 - 4ac] ] / [ 2a] =

[ -2 ±√ [ 2^2 - 4(-3)(-3) ] ] / [ 2 * -3 ] =

[ -2 ±√ [ 4 - 36] ] / [ -6] =

[ -2 ±√-32 ] / [ -6] =

[-2 ±√ [ (-1)(16)(2) ] ] / -6

[-2 ±4i√2 ] / -6 =

[ -1 ± 2i√2 ] / -3 =

[ 1 ±2i√2 ] / 3 ⇒ "B"

For the second one the distance is √[23^2 - 12^2 ] = √385 = 19.6 ft ...correct !!!

CPhill Sep 12, 2018