Question

（2x-3)²=5 3x(x-2)=4-2x (2a+1)²+3（2a+1）+2=0 5（y+6)(y-1)+4y(y-1)=3y(y+6) 帮帮忙解一下方

Answer 1

解
(2x-3)²=5
2x-3=±√5
2x-3=√5或2x-3=-√5
2x=3+√5或2x=3-√5
x1=(3+√5)/2, x2=(3-√5)/2

3x(x-2)=4-2x
3x²-6x=4-2x
3x²-6x+2x-4=0
3x²-4x-4=0
(x-2)(3x+2)=0
x-2=0或3x+2=0
x1=2, x2=-2/3

(2a+1)²+3(2a+1)+2=0
4a²+4a+1+6a+3+2=0
4a²+10a+6=0
2a²+5a+3=0
(a+1)(2a+3)=0
a+1=0或2a+3=0
a1=-1, a2=-3/2

5(y+6)(y-1)+4y(y-1)=3y(y+6)
5(y²+5y-6)+4y²-4y=3y²+18y
5y²+25y-30+4y²-4y-3y²-18y=0
6y²+3y-30=0
2y²+y-10=0
(y-2)(2y+5)=0
y-2=0或2y+5=0
y1=2, y2=-5/2