Problem: The sum of the roots of the equation 4x2+5β8x=04 x^{2}+5-8 x=04x2+5β8x=0 is equal to:
Answer Choices:
A. 888 B. β5-5β5 C. β5/4-5 / 4β5/4 D. β2-2β2 E. none of these answers.
Solution:
x2β8x4+54=0;β΄r1+r2=ββ84=2.x^{2}-\dfrac{8 x}{4}+\dfrac{5}{4}=0 ; \quad \therefore r_{1}+r_{2}=-\dfrac{-8}{4}=2. x2β48xβ+45β=0;β΄r1β+r2β=β4β8β=2.
Answer: E\boxed{E}Eβ.