(3+x)^2-25=0
问题描述:
(3+x)^2-25=0
7+23x-20x^2=0
3-x^2=-2x
19x+10=10x+x^2
5x-18=2(x-50)
3x-11-(x-3)^2=0
有些有两个答案的要标出来!好的+分!
答
(3+x)^2-25=0(3+x+5)(3+x-5)=0(x+8)(x-2)=0x1=-8,x2=27+23x-20x^2=020x^2-23x-7=0(5x-7)(4x+1)=0x1=7/5,x2=-1/43-x^2=-2xx^2-2x-3=0(x-3)(x+1)=0x1=3,x2=-119x+10=10x+x^2x^2-9x-10=0(x-10)(x+1)=0x1=10,x2=-15x-18=...