原式=2(3x²+3y²-5xy)-3(4x²锋仔-3y²+2xy)
=6x²+6y²缓派-10xy-12x²银哪汪+9y²-6xy
=-6x²+15y²-16xy
=-54+5/3-16
=-205/3
2A-3B
=2(3x^2+3y^2-5xy)-3(4x^2-3y^2+2xy)
=6x^2+6y^2-10xy-12x^2+9y^2-6xy
=6x^2-12x^2+6y^2+9y^2-10xy-6xy
=-6x^2+15y^2-16xy
=-6*3^2+15*(1/空桥谨3)^2-16*3*1/3
=-54+5/消梁3-16
=-70+5/斗基3
=-205/3
A=3X平方+3Y平方-5XY
=3*9+1/3-5
=67/3
B=4X平方-3Y平方消滑此+2XY
=4*9-1/3+2
=113/3
所以让橘2A-3B=134/3-339/拿迅3=-205/3
A=3X平方+3Y平方-5XY, B=4X平方-3Y平脊卜裤方+2XY
2A-B=6X^2-4X^2+6Y^2+3Y^2-10XY-2XY=2X^2+9Y^2-12XY
又X=3，Y=1/3
所樱简弊缓以2A-B=2*9+9*(1/9)-12=18+1-12=7
原式=2(3x²+3y²-5xy)-3(4x²锋仔-3y²+2xy)
=6x²+6y²缓派-10xy-12x²银哪汪+9y²-6xy
=-6x²+15y²-16xy
=-54+5/3-16
=-205/3
A=27+1/3-5=67/3
B=36-1/3+2=113/3
答案-205/3