(1)计算:50°24′×3-98°12′25″;(2)计算:;(3)计算:(-2)3+(-3)×[(-4)2+2]-(-3)2÷(-2)(4)计算:1-2(1-2x

发布时间:2020-07-29 16:43:52

(1)计算:50°24′×3-98°12′25″;
(2)计算:;
(3)计算:(-2)3+(-3)×[(-4)2+2]-(-3)2÷(-2)
(4)计算:1-2(1-2x+x2)+3(-x2+x-1);
(5)解方程:2(x-2)-3(4x-1)=5(1-x)
(6)解方程-1

网友回答

解:(1)50°24′×3-98°12′25″,
=150°72′-98°12′25″,
=151°12″-98°12′25″,
=52°59′35″;

(2),
=30÷(-)-1÷×10,
=30÷-1÷×10,
=900-100,
=800;

(3)(-2)3+(-3)×[(-4)2+2]-(-3)2÷(-2),
=(-2)3+(-3)×18-(-3)2÷(-2),
=-8+(-3)×18-9÷(-2),
=-8-54+,
=-57;

(4)1-2(1-2x+x2)+3(-x2+x-1),
=1-2+4x-2x2-3x2+3x-3,
=-5x2+7x-4;

(5)2(x-2)-3(4x-1)=5(1-x),
去括号,得
2x-4-12x+3=5-5x,
移项,合并同类项,得
-5x=6,
系数化为1,得
x=-.

(6)-1,
去分母,得
3(3x+5)=2(2x-1)-6,
去括号,得
9x+15=4x-2-6,
移项,合并同类项,得
5x=-23,
系数化为1,得
x=-.

解析分析:(1)将50°,24′分别与3相乘,然后按照进率将分化为度,然后与98°12′25″相减,即可得出
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