Question

因式分解!

(1)-14abc-7ab+49ab²c (2)(x²+1)²-4x² (3)x²xy+1/4y² (4)3a²-3b²

Answer 1

1。。-14abc-7ab+49ab^c
=-7ab(2c+1)+49ab^c
=7ab(7bc-2c+1)
2..m(x-y)^-x+y
=m(x-y)^-(x-y)
=(x-y)*{m(x-y)-1}
=(x-y)(mx-my-1)
3..9(a-b)^-16(a+b)^ 用a^-b^=(a+b)(a-b)
=3^(a-b)^-4^(a+b)^
={3(a-b)-4(a+b)}{3(a-b)+4(a+b)}
=-(7a+b)(7b+a)

Answer 2

(1)-14abc-7ab+49ab²c
=-7ab(c+1-7bc)

(2)(x²+1)²-4x²
=(x²+2x+1)(x²-2x+1)
=(x+1)²(x-1)²

(3)x²+xy+1/4y²
=(x+1/2y)²

(4)3a²-3b²
=3(a²-b²)
=3(a-b)(a+b)

Answer 3

-7ab(2c+1-7bc)

(x²+1-2x)()(x²+1+2x)=(x-1)^2(x+1)^2

x²+xy+1/4y²
=(x+1/2y)²

3(a-b)(a+b)

Answer 4

fen

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