Integral Compound Expressions.

$x - [2 x + (x - 2 y) + 2 y] - 3 x - \{4 x - [(x + 2 y) - y] \}$ .

$x - [y + z - x - (x + y) - z] + (3 x - \overset{―}{2 y + z})$ .

The expression $- \overset{―}{2 y + z}$ is equivalent to $- (2 y + z)$ .

Consider all the factors that precede $x$ , $y$ , and $z$ , respectively, as the coefficients of these letters, and collect in brackets the coefficients of each of these letters:

$a x + b y + c z - a y + a z - b x = (a - b) x - (a - b) y + (a + c) z$ .

$a x + a z + b y - c z - a y + c x$ .

$2 a x - 3 a y - 4 b y + 5 c x - 6 b z - 7 c z$ .

$a z - b m y + 3 c z - a n x - c n y + a c x$ .

$m n x - x - m n y - y + m n z + z$ .