Answer:
B. (1 ± sqrt(33)) / 4
Step-by-step explanation:
the 2 solutions for a quadratic equation
ax² + bx + c = 0
are defined as
x = (-b ± sqrt(b² - 4ac)) / 2a
in our example here we have
a = -2
b = 1
c = 4
=>
x = (-1 ± sqrt(1 + 32)) / -4 = (1 ± sqrt(33)) / 4
as we can easily divide top and bottom by -1 to turn the -1 and -4 into positive numbers, and the second top part, the square root, is a ± factor anyway. just withing the sign dues not change the fact that is is still a ± factor (both signs apply).
and now it is clear, it has to be option B.
the others disqualify because they have either no division by any form of 4, or the "1" and the "4" have different signs. but our equation shows they need to have equal signs (either both negative or both positive).
