(1)6x^2-7x+1=0 (2)5x^2-9x-18=0 (3)4x^2-3x=52 (4)5x^2=4-2x

题目

(1)6x^2-7x+1=0 (2)5x^2-9x-18=0 (3)4x^2-3x=52 (4)5x^2=4-2x

答案

(1)6x^2-7x+1=0(6X-1)(X-1)=0 则X=1或1/6(2)5x^2-9x-18=0 （5X+6）*（X-3）=0 则X=-6/5或33)4x^2-3x=52 4X^2-3X-52=0(X-4)(X+13)=0 X=4或-135X^2+2X-4=0 5(X+1/5)^2-4-5*(1/5)^2=0 5(X+1/5)^2=21/5 (X+1/5)^2=21/25 ...