分解因式a²-16(a-b)²

分解因式a²-16(a-b)²
分解因式a²-16(a-b)²

分解因式a²-16(a-b)²
a" - 16( a - b )"
= a" - [ 4(a - b ) ]"
= a" - ( 4a - 4b )"
= ( a + 4a - 4b )( a - 4a + 4b )
= ( 5a - 4b )( -3a + 4b )
= -( 3a - 4b )( 5a - 4b )

a²-16(a-b)²
=[a-(4a-b)][a+4(a-b)]
=(a-4a+b)(a+4a-b)
=(b-3a)(5a-b)
套用公式a²-b²=（a+b）（a-b）

a²-16(a-b)²
=[a-(4a-b)][a+4(a-b)]
=(a-4a+b)(a+4a-b)
=(b-3a)(5a-b)[a-(4a-b)][a+4(a-b)] 这个怎么来的平方差公式：a²-b²=(a+b)(a-b)
a²-16(a-b)²
=a²-[4(a-b)]
...

全部展开

a²-16(a-b)²
=[a-(4a-b)][a+4(a-b)]
=(a-4a+b)(a+4a-b)
=(b-3a)(5a-b)

收起

a的平方-（4a-4b)(4a-4b)
[a+(4a-4b)][a-(4a-4b)]