X^2+x+6xy+3y+9y^2 если x+3y=-7

Question

X^2+x+6xy+3y+9y^2 если x+3y=-7

Answer 1

Х²+х+6ху+3у+9у² = (х²+6ху+9у²)+(х+3у) = (х+3у)²+(х+3у) = (-7)²+(-7) = 49-7 = 42

Answer 2

(x²+2*3y*x +(3y)² )+x+3y = (x+3y)²+x+3y = (-7)²+3y= 49+3y+x=49-7=42

Comments

а просто х? потерялси?(