题目内容
(1)一个多项式减去-4x2-2x+1等于3x2+4x-1,求这个多项式.
(2)先化简,再求值:
a-2(a-
b2)+(-
a+
b2),期中a=-2,b=
.
(2)先化简,再求值:
1 |
2 |
1 |
3 |
3 |
2 |
1 |
3 |
2 |
3 |
(1)-4x2-2x+1+(3x2+4x-1)
=-4x2-2x+1+3x2+4x-1
=-4x2+3x2-2x+4x-1+1
=-x2+2x;
(2)
a-2(a-
b2)+(-
a+
b2)
=
a-2a+
b2-
a+
b2
=-3a+b2;
当a=-2,b=
时,
原式=-3×(-2)+(
)2=6+
=6
.
=-4x2-2x+1+3x2+4x-1
=-4x2+3x2-2x+4x-1+1
=-x2+2x;
(2)
1 |
2 |
1 |
3 |
3 |
2 |
1 |
3 |
=
1 |
2 |
2 |
3 |
3 |
2 |
1 |
3 |
=-3a+b2;
当a=-2,b=
2 |
3 |
原式=-3×(-2)+(
2 |
3 |
4 |
9 |
4 |
9 |
练习册系列答案
相关题目