因式分解计算 (18 20:3:56)(3y-1)^2=(y-3)^2已知a^2+2ab+2b^2-6b+9=0,求a-b的值
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因式分解计算 (18 20:3:56)(3y-1)^2=(y-3)^2已知a^2+2ab+2b^2-6b+9=0,求a-b的值
因式分解计算 (18 20:3:56)
(3y-1)^2=(y-3)^2
已知a^2+2ab+2b^2-6b+9=0,求a-b的值
因式分解计算 (18 20:3:56)(3y-1)^2=(y-3)^2已知a^2+2ab+2b^2-6b+9=0,求a-b的值
已知a^2+2ab+2b^2-6b+9=0,求a-b:
a^2+2ab+2b^2-6b+9=0
(a+b)^2+(b-3)^2=0
b=3,a=-3
a-b=-3-3=-6
我永远是对的.
1、(3y-1)^2=(y-3)^2
9y^2-6y+1-y^2+6y-9=0
8y^2-8=0
8(y^2-1)=0
(y+1)(y-1)=0
y=1或y=-1
2、a^2+2ab+2b^2-6b+9=0
a^2+2ab+b^2+b^2-6b+9=0
(a+b)^2+(b-3)^...
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1、(3y-1)^2=(y-3)^2
9y^2-6y+1-y^2+6y-9=0
8y^2-8=0
8(y^2-1)=0
(y+1)(y-1)=0
y=1或y=-1
2、a^2+2ab+2b^2-6b+9=0
a^2+2ab+b^2+b^2-6b+9=0
(a+b)^2+(b-3)^2=0
(a+b)^2≥0,(b-3)^2≥0
所以:
a+b=0,b-3=0
b=3,a=-3
所以:
a-b=-3-3=-6
收起
y=1或y=-1
a-b=-6
可因式分解为(a+b)^2+(b-3)^2=0,两数平方和为0,那么两数分别为0,所以b=3,a=-3,a-b=-3-3=-6