当x取何值时,代数式2x+3与-5x+2的值:
[1]相等?
[2]互为相反数?
1.2x+3=-5x+2
x=-1/7
2.2x+3=5x-2
x=5/3
[1] 2x+3=-5x+2
7X= -1
X= -1/7
[2] 2x+3+(-5x+2)=0
3x=5
x=2又3分之2