Question

x的四次方-18x的平方+8怎么因式分解？还有b的平方+c的平方-2bc-a的平方怎么因式分解？

x的四次方-18x的平方+81，我看错了

Answer 1

x的四次方-18x的平方+81
=(x²-9)²
=(x+3)²(x-3)²
b²+c²-2bc-a²
=(b-c)²-a²
=（b-c+a)(b-c-a)

Answer 2

x^4 - 18x" + 81
= (x")" - 2(9x") + 9"
= ( x" - 9 )"
= ( x" - 3" )"
= ( x + 3 )"( x - 3 )"

b" + c" - 2bc - a"
= ( b" - 2bc + c" ) - a"
= ( b - c )" - a"
= ( b - c + a )( b - c - a )
= -( a + b - c )( a - b + c )

Answer 3

x^4-18x+81=(x²-9) ²=(x-3)²(x+3)²