$${3x+4y-2z+9=17},{7x+2y+11z+8=23}$$ and $$ {5x+9y+6z-4=18}$$ then what is  the value of $$ {x+y+z-34}$$?

(x+2y) (x² + 4y² – 2xy) equal to- 

If (a-b)=-3 , (b-c)=5 and (c-a)=-2, then the value of $$ {a^{3}+b^{3}+c^{3}-3abc\over a+b+c}$$.

If $$ {P={96\over95×97}},{Q={97\over96×98}}$$ and $$ {R={1\over97}}$$ then which of the following is True?

If x - y = 6 and xy = 40, then  find $$ {x^2+y^2}$$

Given k = -3. Find the value of $$ {k^3+3k}$$. 

If a+b = 1 and a³+b³+3ab=k, then the value of k is : 

If x = b+c -2a, y=c+a-2b, z=a+b-2c, then the value of x²+y²-z²+2xy is :