6x'2-7x+1=o;5x'2-18=9x；4x'2-3x=52;5x'2=4-2x.

(6x-1)*(x-1) = 0 x = 1/6 或 x = 1(x-3)(5x-6)= 0 x=3或x = 6/5(x-4)*(4x+13)=0x = 4 或x = - 13/45x^2 +2x - 4 = 0 a = 5,b =2 c = -4b^-4ac = 84>0x =-2+根号84）/10 x =-2-根号84）/10 即：x = （-1+根号21）/5x...谢谢喽只有最后一个不用因式分解法其它都可以用哦哦，只讲第一个6x'2-7x+1=06 -1 1 -1当6*（-1）+1*(-1) = -6-1=-7 时正好是一次项系数此时 可以写成（6x-1)*(x-1) = 0即 6x - 1 = 0 或 x-1 = 0∴ x = 1/6 x = 1其它都一样最后一个是用公式法x = [-b+根号（b^2 - 4ac)]/2x = [-b-根号（b^2 - 4ac)]/2就可以了。不清楚 再说 好不好？