Find the total distance  travelled  by him before 

If (a + b) = 7 and ab = 9, then find the value of (a² + b²).

If (a - b - c) = 6, and (ab - bc + ca) = 117, then find the value of (a ²  + b ²  + c ² )

If (3x - y) = 3, xy = (2/3), then find the value of {x³ - (y³/27)}

If  (a³+1)/(a+1) = (a³-1)/(a-1) and a ≠ 1, -1. Find the value of  'a'

What will come in the place of question mark (?) in the given expression?

?² = (392 × 224) ÷ (112 × 28) + 6²

If 9x² + y² = 37 and xy=2, x, y>0, then the value of (27x³ + y³) is:

If 0.125x³ +0.216y³ = 210 and 0.25x² + 0.36y² = 10.30 then find the value of 0.5x + 0.6y.

Simplify:
7x + 9y - [(14x + 5y) - (5x + 3y) + 4y] - 5x