if 2x² – 7x + 5 =0, then what is the value of

if then what is the value of =?

 if , then what is the value of (2a+3b)?

If (x + y)³ +8 (x - y)³ = (3x+ Ay)(3x²+ Bxy+ Cy²), then the value of A+B+C is:

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

If (10 a³+4b³):(11a³-15b³)=7:5, then (3a+5b):(9a-2b)=?

The expression   is equal to:

 If 3x²-5x+1=0, then the value of ( ) is