How do you solve #5x^2 + 9x - 2 =0# using the quadratic formula?

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Answer 1 · 2016-03-20T03:14:55

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Factoring
Quadratic formula

Answer 2 · 2016-03-20T05:27:37

#x=1/5,-2#

#color(blue)(5x^2+9x-2=0#

This is a Quadratic equation (in form #ax^2+bx+c=0#)

Use Quadratic equation

#color(brown)(x=(-b+-sqrt(b^2-4ac))/(2a)#

Where

#color(red)(a=5,b=9,c=-2#

Substitute the values

#rarrx=(-9+-sqrt(9^2-4(5)(-2)))/(2(5))#

#rarrx=(-9+-sqrt(81-4(5)(-2)))/(10)#

#rarrx=(-9+-sqrt(81-(-40)))/(10)#

#rarrx=(-9+-sqrt(81+40))/(10)#

#rarrx=(-9+-sqrt(121))/10#

#rArrx=(-9+-11)/(10)#

Now we have #2# solutions

#color(orange)(rArrx=(-9+11)/(10)=2/10=1/5#

#color(indigo)(rArrx=(-9-11)/(10)=-20/10=-2#

#color(green)( ul bar|:.x=1/5,-2|#