若(xx)+(yy)-4x+6y+13=0,求2x+3y的值?
问题描述:
若(xx)+(yy)-4x+6y+13=0,求2x+3y的值?
答
(xx)+(yy)-4x+6y+13=0
(xx)-4x+(yy)+6y+13=0
(xx)-4x+4+(yy)+6y+9=0
(x-2)²+(y+3)²=0
x-2=0 y+3=0
x=2 y=-3
2x+3y=2×2-3×3=-5