x2⃣️-3x=-2/3;x2⃣️-3x+(3/2)2⃣️=-2/3+(3/2)2⃣️;(x-3/2)2⃣️=19/12;
解得X1=(9+根57)/6
X2=(9-根57)/6
2、Xl=2;X2=3/2
3、Xl=4+根19;X2=4-根19
第一题步骤即可得出后两题
3x²-9x+2=0
x²-3x+2/3=0
(x-(3/2))²+2-9/4=0
(x-(3/2))²=1/4
x=3/2 ± 1/2
x=1或2
2x²+6=7x
x²-(7/2)x+3=0
(x-(7/4))²= -3+49/16
(x-(7/4))²=1/16
x=7/4 ± 1/4
x=2或 3/2
4x²-8x-3=0
x²-2x-3/4=0
(x-1)²=3/4 +1
x-1=±(根号7)/2
x=1±((根号7)/2)
求采纳