6X?-7X+1=0
解:6X?-7X=-1
X?-﹙7/6﹚X+﹙7/12﹚?= -1/6﹢﹙7/12﹚?
﹙ X-7/12﹚?=25/144
∴X-7/12=±5/12 p>
∴X1=1,X2=1/6
5X?-18=9X
解:5X?-9X=18
X?-1.8X=3.6
﹙ X-0.9﹚?=4.41
∴X-.9=±2.1
∴X1=3,X2 =-1.2
4X?-3X=52
解:X?-﹙3/4﹚X=13
﹙X-3/8﹚ ?=13
∴X-3/8=±29/8
∴X1=4,X2 =-13/4
5X?=4 -2X
解:5X?+2X=4
X?+0.2X=0.8
﹙X+0.1﹚? =0.81
X+0.1=±0.9
X1=-1,X2=0.8