2) v?? ?? - ?? = ?? v?? ?? = 3 X = ?? v?? X = v?? s.s = { v?? } 3) ?? ?? - v?? = ??v?? 7 x = 7 v?? X = v?? s.s = { v?? } 4) ?? - v?? = ?? X = 1 + v?? s.s = { 1 + v?? } 1ST TERM MATH-PREP.2 49 | P a g e