Question

PLEASE HELP ME Solve -2x^2+3x-9=0

a. x=(3+/-3i)sqr7/4
b. x=(3+/-9i)sqrt7/4
c. x=(-3+/-3i)sqrt7/4
d. x=-3+/-9i)sqrt7/4

Answer 1

{"x = 3/4 (1-i sqrt(7)) ~~ 0.75-1.98431 i", "x = 3/4 (1+i sqrt(7)) ~~ \
0.75+1.98431 i"}

Answer 2

Thats not right..

Answer 3

Divide both sides by -2:
x^2-(3 x)/2+9/2 = 0
Subtract 9/2 from both sides:
x^2-(3 x)/2 = -9/2
Add 9/16 to both sides:
x^2-(3 x)/2+9/16 = -63/16
Factor the left hand side:
(x-3/4)^2 = -63/16
Take the square root of both sides:
sqrt(x-3/4)^2 = (3 i sqrt(7))/4
Eliminate the absolute value:
x-3/4 = -(3 i sqrt(7))/4 or x-3/4 = (3 i sqrt(7))/4
Add 3/4 to both sides:
x = 3/4 (1-i sqrt(7)) or x-3/4 = (3 i sqrt(7))/4
Add 3/4 to both sides:
x = 3/4 (1-i sqrt(7)) or x = 3/4 (1+i sqrt(7))