Question

高一数学题,求解

题在图里

Answer 1

求助得到的回答
1、
=(4a²b^4)(3a²b-2ab-1)
=12a^4b^5-8a³b^5+4a²b^4

2、
=4(a²-2ab+b²)-(2a+b)(2a-b)
=4a²-8ab+4b²-4a²+b²
=-8ab+5b²

3、
=[x-(y-1)][x+(y-1)]
=x²-(y-1)²
=x²-y²+2y-1

4、
=(x+3y)(x-3y)(x²+9y²)
=(x²-9y²)(x²+9y²)
=x^4-81y^4

Answer 2

原式=(x²+3x+9)/(x-3)(x²+3x+9)-6x/x(x+3)(x-3)+(x-1)/2(x+3)
=1/(x-3)-6/(x+3)(x-3)+(x-1)/2(x+3)
=[2(x+3)-12+(x-1)(x-3)]/[2(x+3)(x-3)]
=(2x+6-12+x²-4x+3)/[2(x+3)(x-3)]
=(x²-2x-3)/[2(x+3)(x-3)]
=(x-3)(x+1)/[2(x+3)(x-3)]
=(x+1)/(2x+6)