to minimise the length, term with \'m\' should be reduced so first to absolute values must be opened with negative sign S2 = -4m+1 - 5m+6 + 10m-3 S2 = m+4 Solution to minimise the length, term with \'m\' should be reduced so first to absolute values must be opened with negative sign S2 = -4m+1 - 5m+6 + 10m-3 S2 = m+4.