Question

若方程组ax+2y=2 x-y=-3b 有无穷多解,则3ax+3=b的解是——.

Answer 1

ax+2y=2 (1)

x-y=-3b (2)

(1)+2*(2)

(a+2)x=2-6b

因为有无穷多解

所以a+2=0,2-6b=0

a=-2,b=1/3

-6x+3=1/3

x=4/9