How do you solve #2x^2 - 10x + 7 = 0# using the quadratic formula?

1 Answer
Mar 20, 2018

Answer:

#x=(5+sqrt11)/2# or #x=(5-sqrt11)/2#

Explanation:

Quadratic formula gives the solution of a quadratic equation. For a quaddratic equation #ax^2+bx+c=0#, the roots given by quadratic formula are #(-b+-sqrt(b^2-4ac))/(2a)#.

Hence for #2x^2-10x+7=0#, we have #a=2#, #b=-10# and #c=7# and hence solution is

#(-(-10)+-sqrt((-10)^2-4*2*7))/(2*2)#

= #(10+-sqrt(100-56))/4#

= #(10+-sqrt44)/4#

= #(10+-2sqrt11)/4#

i.e. either #x=(5+sqrt11)/2# or #x=(5-sqrt11)/2#