用因式分解发解下列方程(1)x^2-25=0.(2)5a^2=4a.(3)¼y^2-y+1=0.(4)x^2-8x+6=0.
问题描述:
用因式分解发解下列方程(1)x^2-25=0.(2)5a^2=4a.(3)¼y^2-y+1=0.(4)x^2-8x+6=0.
答
解
x²-25=0
(x+5)(x-5)=0
∴x=5或x=-5
5a²=4a
5a²-4a=0
a(5a-4)=0
∴a=0
或a=4/5
1/4y²-y+1=0
(1/2y-1)²=0
∴1/2y-1=0
∴y=2
x²-8x+6=0
(x-6)(x-2)=0
∴x=6
或x=2