How do you solve #2x^2 + 3x - 4 = 0# by completing the square?

Question

2681 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-04-25T11:07:50

Solution: #:. x ~~ -2.35 , x ~~ 0.85 #

#2 x^2+3 x-4=0 or 2( x^2+1.5 x) -4 =0# or

#2( x^2+1.5 x +0.75^2) -2*0.75^2 -4 =0 # or

#2( x+0.75)^2 -5.125 =0# or

#2( x+0.75)^2 =5.125 # or

#( x+0.75)^2 =5.125/2 # or

#( x+0.75)^2 = 2.5625 # or

#( x+0.75) =+- sqrt 2.5625 #

#:. x ~~ -0.75+- 1.6 #

#:. x ~~ -2.35 , x ~~ 0.85 #

Solution: #:. x ~~ -2.35 , x ~~ 0.85 # [Ans]