What makes 1, 2,5, and 8 using -2, 5, 3, and -7?
5 · 3 - (-2 · -7) = 15 - (14) = 1
(-7 - 5) / (-2 · 3) = -12 / -6 = 2
5 / ( 3 · -2 - -7 ) = 5 / ( -6 + 7 ) = 5 / 1 = 5
-(-7) - ( 3 · -2 + 5 ) = 7 - ( -6 + 5 ) = 7 - (-1) = 8