题目内容
计算:
(1)(-
)-2+(
)0+(-5)3÷(-5)2
(2)(4m-3)2+(4m+3)(4m-3)
(3)-10
×9
(4)已知x2+4x-1=0,求2x4+8x3-4x2-8x+1的值.
(1)(-
1 |
3 |
1 |
9 |
(2)(4m-3)2+(4m+3)(4m-3)
(3)-10
2 |
7 |
5 |
7 |
(4)已知x2+4x-1=0,求2x4+8x3-4x2-8x+1的值.
(1)原式=9+1+(-5)
=5;
(2)原式=(4m-3)(4m-3+4m+3)
=8m(4m-3)
=32m2-24m;
(3)原式=-(10+
)(10-
)
=-(100-
)
=-99
;
(4)∵x2+4x-1=0,
∴2x4+8x3-4x2-8x+1
=2x2(x2+4x-1)-2(x2+4x-1)-1
=-1.
=5;
(2)原式=(4m-3)(4m-3+4m+3)
=8m(4m-3)
=32m2-24m;
(3)原式=-(10+
2 |
7 |
2 |
7 |
=-(100-
4 |
49 |
=-99
45 |
49 |
(4)∵x2+4x-1=0,
∴2x4+8x3-4x2-8x+1
=2x2(x2+4x-1)-2(x2+4x-1)-1
=-1.
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