习题11.3第1题答案
解:(1)原式=(4×8)·(a3·a2)=32a⁵;
(2)原式=(2×3×1)·(x2·x)·(y2· y·y⁵)·(z·z3·z)=6x3y⁸z⁵;
(3)原式=(2×3)·(a·a2)·(b2·b)·c2=6a3 b3 c2;
(4)原式=[(-4)×(-5)]·(x2·x)·(y·y3) =20x3y⁴
习题11.3第2题答案
习题11.3第3题答案
解:(1)原式=2x·(-4x)-1/2·(-4x)=-8x2 +2x;
(2)原式=3xy·x2 y- 3xy·xy= 3x3 y2=3x2 y2
习题11.3第4题答案
解:(1)原式=3a2 -10a-3a2=-10a;
(2)原式=t2+4t+3t2+3=4t2+4t+3;
(3)原式=2x3 -4x2+2x;
(4)原式=-a2b2+3a3 b+4a2
习题11.3第5题答案
解:(1)原式=x⁴- x3+x2=x⁴+x3 -x2 +x=x
当x=1/2时,原式=x=1/2
(2)原式=x3 +x-x3+3x2-3x2-3x+3= -2x+3,
当x=1/5时,
原式=-2x+3=-2×1/5+3=-2/5+3=13/5
习题11.3第6题答案
解:(1)原式=9x2y⁴+4x2y⁴=13x2y4;
(2)原式=t3 -2t(t2 -2t+6)
=t3-2t3+4t2 -12t
=-t3+4t2 -12t
习题11.3第7题答案
解:(1)化简,得6x2-6x2-4x+ 9x=-10,即5x=-10,x= -2;
(2)化简,得24x-78x2+54x=-13-78x2,即65x=-13, x=-1/5
习题11.3第8题答案
解:因为AB=b,DC=a,
又因为四边形ABEF是正方形,
所以AB=AF=EF=BE=b
因为DF+EF+EC=CC=a,
所以DF+EC=DC-EF=a-b
S阴影=S▵AFD+S▵BEC
=1/2DF·AF+1/2 EC·BE
=1/2DF·b+1/2EC·b
=1/2b(DF+EC)1/2b(a-b)
=1/2ab-1/2b2