= -3/2 * -5 1/4
convert 5 1/4 to improper fraction
= -3/2 * -21/4
multiply numerators; multiply denominators
= (-3*-21)/(2*4)
multiply in parentheses
= 63/8
convert back to mixed number
= 7 7/8
ANSWER: Since the exact answer is the mixed number 7 7/8, a reasonable estimate is 8.
Hope this helps! :)