Does someone know One of the solutions of 5x2 + 9x - 2 = 0 is?

5x² + 9x - 2 = 0
x = [ - 9 ± √ (81 + 40 ) ] / 10
x = [ - 9 ± √ (121) ] / 10
x = [ - 9 ± 11 ] / 10
x = 2 / 10 , - 20 / 10
x = 1 / 5 , x = - 2
OPTION c) is one of the solutions.

(5x-1)(x+2)=0
x=1/5,-2

To solve a quadratic either factor it or use the quadratic equation.

(5x - 1)(x + 2)
The two solutions are -2 and 0.2
(so c) )

The shortcut with multiple choice is just plug each answer back into the equation and see if it works

attempt subbing in aspects of 40 5 (which comprise detrimental) into x and you will probable locate the ideas :) (there will be 3 as this is a cubic) this is probable greater effective than me telling you the respond :P stressful, i be responsive to, sorry

By factoring:
5x2 + 9x - 2 = 0
(5x - 1)(x + 2) = 0
Roots:
x = 1/5 <--- (c)
x = -2

Factorise it to (5x - 1)(x + 2) = 0

5x - 1 = 0
5x - 1 (+1) = 0 (+1)
5x = 1
5x (/5) = 1(/5)
x = 1/5

alternately

x + 2 = 0
x + 2 (-2) 0 (-2)
x = -2

So solution set = -2 or 1/5

From your numbers, only 1/5 (c) works XD

Hope this helps :D

x = {-b ± √[b^2 - 4ac]}/2a
x = {-9 ± √[9^2 - 4(5)(-2)]}/2(5)
x = {-9 ± √[81 + 40]}/10
x = {-9 ± √121}/10
x = {-9 ± 11}/10
x1 = (-9 + 11)/10
x1 = 1/5
x2 = (-9-11)/10
x2 = -2

I'd say that the answer(s) is(are)
-2 and/or 1/5

5x^2 + 9x - 2 = 0
(5x - 1)(x + 2) = 0

5x - 1 = 0
5x = 1
x = 1/5 (0.2)

x + 2 = 0
x = -2

∴ x = 1/5 (0.2) , -2
(answer c)