Medium Arithmetic Puzzles

#1961: 4 _ 6 _ 8 _ 8 = -5 medium #1963: 4 _ 6 _ 8 _ 9 = -6 medium #1965: 4 _ 6 _ 9 _ 3 = 6 medium #1966: 4 _ 6 _ 9 _ 6 = 8 medium #1970: 4 _ 6 _ 9 _ 2 = 8 medium #1972: 4 _ 6 _ 9 _ 2 = 12 medium #1973: 4 _ 6 _ 9 _ 3 = 9 medium #1975: 4 _ 6 _ 9 _ 4 = 10 medium #1983: 4 _ 6 _ 9 _ 8 = -2 medium #1986: 4 _ 7 _ 2 _ 3 = 11 medium #1987: 4 _ 7 _ 2 _ 4 = 10 medium #1997: 4 _ 7 _ 4 _ 8 = 14 medium #1998: 4 _ 7 _ 4 _ 2 = 14 medium #2002: 4 _ 7 _ 8 _ 4 = 14 medium #2003: 4 _ 8 _ 2 _ 4 = 8 medium #2005: 4 _ 8 _ 2 _ 3 = -8 medium #2009: 4 _ 8 _ 2 _ 5 = 11 medium #2010: 4 _ 8 _ 2 _ 6 = 10 medium #2011: 4 _ 8 _ 2 _ 7 = 9 medium #2018: 4 _ 8 _ 2 _ 5 = -4 medium #2020: 4 _ 8 _ 2 _ 6 = -5 medium #2021: 4 _ 8 _ 2 _ 7 = 8 medium #2022: 4 _ 8 _ 2 _ 7 = -6 medium #2023: 4 _ 8 _ 2 _ 8 = 9 medium #2024: 4 _ 8 _ 2 _ 8 = -7 medium #2025: 4 _ 8 _ 2 _ 9 = 10 medium #2028: 4 _ 8 _ 3 _ 4 = 10 medium #2029: 4 _ 8 _ 3 _ 6 = 8 medium #2031: 4 _ 8 _ 3 _ 2 = -8 medium #2036: 4 _ 8 _ 4 _ 3 = 10 medium #2041: 4 _ 8 _ 4 _ 5 = -6 medium #2042: 4 _ 8 _ 4 _ 6 = -8 medium #2048: 4 _ 8 _ 4 _ 7 = 14 medium #2051: 4 _ 8 _ 5 _ 4 = -6 medium #2053: 4 _ 8 _ 5 _ 6 = 15 medium #2056: 4 _ 8 _ 6 _ 3 = 8 medium #2058: 4 _ 8 _ 6 _ 4 = -8 medium #2068: 4 _ 8 _ 6 _ 4 = 12 medium #2069: 4 _ 8 _ 6 _ 5 = 8 medium #2071: 4 _ 8 _ 6 _ 5 = 15 medium #2072: 4 _ 8 _ 6 _ 6 = 9 medium #2074: 4 _ 8 _ 6 _ 7 = 10 medium #2075: 4 _ 8 _ 6 _ 7 = -4 medium #2076: 4 _ 8 _ 6 _ 8 = 11 medium #2077: 4 _ 8 _ 6 _ 8 = -5 medium #2079: 4 _ 8 _ 6 _ 9 = -6 medium #2081: 4 _ 8 _ 7 _ 4 = 14 medium #2084: 4 _ 8 _ 9 _ 2 = 9 medium