If Selling Price is 9 per unit, variable cost is 5 per

Simplify:
4x + 6y - [(8x + 5y) - (3x + 2y) + 3y] - 2x

If 112 ÷28 x 2² –12 x 6 ÷ 3 +12 = z, then find the value of z.

If a = (√2 - 1)^1/3, then the value of (a-1/a)³ +3(a-1/a) is:

Solve for x in the equation: 3(x + 2) + 2(2x - 5) = 5x + 9

If p = 32 - q - r and pq + r(q + p) = 255, then find the value of (p² + q² + r²).

If a + b + c = 9 and ab + bc + ca = 20, then find the value of a² + b² + c².

If, ( a + b = 8 ) and ( a² + b² = 40 ), then find the value of (a³ + b³). 

f(y) = y² – 5y + 6. Determine f(3) + f(–2).

If the sum of three numbers is zero, then which of the options below will always be equal to the value of the sum of the cubes of those numbers?