Question

急！！！！！！ 帮帮忙！！！！ T^T 数学 如果可以的话，加上这题是怎么做的T^TT^T

Answer 1

(1) 2x^2-7x=3x-5
2x^2-10x=-5
x^2-5x=-5/2
x^2-5x+25/4=-5/2+25/4
(x-5/2)^2=15/4
x-5/2=正负(根号15)/2
x1=(5+根号15)/2, x2=(5-根号15)/2.
(2) x(x-6)-2(x+8)=0
x^2-6x-2x-16=0
x^2-8x=16
x^2-8x+16=16+16
(x-4)^2=32
x-4=正负4根号2
x1=4+4根号2， x2＝4-4根号2.
(3) y^2-6x+3=0
y^2-6y=-3
y^2-6y+9=-3+9
(y-3)^2=6
y-3=正负根号6
y1=3+根号6， y2=3-根号6.
(4) y(y-1)-3y^2=0
y^2-y-3y^2=0
2y^2+y=0
y(2y+1)=0
y1=0, y2=-1/2.
(5) (2x+1)^2=4x+2
(2x+1)^2-2(2x+1)=0
(2x+1)[(2x+1)-2]=0
(2x+1)(2x-1)=0
x1=-1/2, x2=1/2.
(6) (x+1)^2-4x^2=0
[(x+1)+2x][(x+1)-2x]=0
(3x+1)(-x+1)=0
x1=-1/3, x2=1.