Answer:
a)
b)
, 
Step-by-step explanation:
a) Since the fraction you are dealing with,
, is positive, we will need to find a fraction that has either two negative numbers or two positive numbers. The first option,
, the entire fraction is negative, which does not match the given fraction. The second option,
, only one number is negative, and that does not match either. The third option,
, is the same as the second option, only one negative number. However the last option,
, has both a negative number in the numerator and denominator which both cancel out to
, making the fraction positive.
b) The fraction we are dealing with here,
, is negative, so we need to find a fraction that has only one negative number. The first option,
, has no negative numbers, making it positive, which does not match. The second option,
, has one negative number, which matches our fraction. The third fraction,
has two negative numbers making the fraction
, positive, which does not match. Then the last option,
the whole fraction is negative which matches our fraction.