(1)解方程:(x-3)2+4x(x-3)=0.(2)解方程:2x2-4x-7=0(3)计算:12+|3-2|+(2-π)0.(4)24-12-2(3-1).-数学

题目简介

(1)解方程:(x-3)2+4x(x-3)=0.(2)解方程:2x2-4x-7=0(3)计算:12+|3-2|+(2-π)0.(4)24-12-2(3-1).-数学

题目详情

(1)解方程:(x-3)2+4x(x-3)=0.
(2)解方程:2x2-4x-7=0
(3)计算:
12
+|
3
-2|+(2-π)0

(4)
24
-
1
2
-
2
(
3
-1)
题型:解答题难度:中档来源:不详

答案

(1)把左边分解因式得:(x-3)(x-3+4x)=0,
x-3=0,x-3+4x=0,
解得:x1=3,x2=class="stub"3
5


(2)a=2,b=-4,c=-7,
b2-4ac=16-4×2×(-7)=72,
x=
-b±
b2-4ac
2a
=
72
4
=
2±3
2
2

x1=
2+3
2
2
,x2=
2-3
2
2


(3)原式=2
3
+2-
3
+1
=
3
+3;

(4)原式=2
6
×
2
2
-
6
+
2

=2
3
-
6
+
2

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