Solve −2x2 − 16x − 44 = 0. x equals negative 8 plus or minus I square root of 6 x equals negative 8 plus or minus 2i square root

Question

algol [13]

4 years ago

5

Solve −2x2 − 16x − 44 = 0. x equals negative 8 plus or minus I square root of 6 x equals negative 8 plus or minus 2i square root

of 6 x equals negative 4 plus or minus i square root of 6 x equals negative 4 plus or minus 2i square root of 6

Mathematics

2 answers:

iragen [17] · Answer 1 · 2021-10-23T18:16:55+03:00

iragen [17]4 years ago

7 0

x^2 + 8x + (4)^2 - (4)^2 + 22 = 0

(x + 4)^2 - 16 + 22 = 0, so that (x+4)^2 + 4 = 0.

Then sqrt( (x+4)^2 = sqrt(-4)

I JUST TOOK THE FLVS TEST

its c

x=-4 plus or minus i sqrt 6

lina2011 [118] · Answer 2 · 2021-10-23T17:07:57+03:00

I would immediately reduce this by div. every term by -2:

x^2 + 8x + 22 = 0

Next, I'd "complete the square:"

x^2 + 8x + (4)^2 - (4)^2 + 22 = 0

(x + 4)^2 - 16 + 22 = 0, so that (x+4)^2 + 4 = 0.

Then sqrt( (x+4)^2 = sqrt(-4)

x+4 = plus or minus i*2

x = -4 plus or minus i*2 (answer)