Question

用因式分解法解下列方程

用因式分解法解下列方程
1.25X的平方-1=0
2.x(x-3)+(x-3)=0
3.4x(x-3)=3x-9
4.(2m+1)的平方+3（2m+1）+2=0
急啊

Answer 1

（1）5X²+4x=0
x(5x+4)=0
x=0或5x+4=0
x1=0,
x2=-4/5
(2)√2y²=3y
3y-√2y²=0
y(3-√2y)=0
y=0或3-√2y=0
y1=0,
y2=(3/2)√2
(3)x²+7x+12=0
(x+3)(x+4)=0
x+3=0或x+4=0
x1=-3,
x2=-4
(4)x²-10x+16=0
(x-2)(x-8)=0
x-2=0或x-8=0
x1=2,
x2=8
(5)x²+3x-10=0
(x+5)(x-2)=0
x+5=0或x-2=0
x1=-5,
x2=2
(6)x²-6x-40=0
(x-10)(x+4)=0
x-10=0或x+4=0
x1=10,
x2=-4
(7)t(t+3)=28
t²+3y-28=0
(t+7)(t-4)=0
t+7=0或t-4=0
t1=-7,
t2=4
(8)(x+1)(x+3)=15
x²+4x+3=15
x²+4x-12=0
(x+6)(x-2)=0
x+6=0或x-2=0
x1=-6,
x2=2