解原式=3x²-7x+(4x+3)+2x²-3=(3x²+2x²)+(4x-7x)+(3-3)=5x²-3x=5×(-1)²-3×(-1)=5+3=8原式=3xy+10y+5x-(2xy+2y-3x)=(3xy-2xy)+(10y-2y)+(5x+3x)=8x+xy+8y=8(x+y)+xy=8×3+2=24+2=26...