hand+job+blow+job

闾妻哄3658若1/a+1/b+1/c=1/a+b+c,求证a,b,c三个数中必有两个数互为相反数. -
向姬肥18486147452 ______[答案] 由1/a+1/b+1/c=1/(a+b+c),得: 1/(a+b+c)-1/a=1/b+1/c, -(b+c)/a(a+b+c)=(b+c)/bc, 所以(b+c)*[1/bc+1/a(a+b+c)]=0, 所以b+c=0,或 1/bc+1/a(a+b+c)=0. 同理可得: a+c=0,或 1/ac+1/b(a+b+c)=0; a+b=0,或 1/ab+1/c(a+b+c)=0; 综上,可知...

闾妻哄3658因式分解ab+cd+bc+ad= -
向姬肥18486147452 ______[答案] ab+cd+bc+ad=a(b+d)+c(b+d)=(b+d)(a+c)

闾妻哄3658若a,b为有理数,且a,b满足a^2+2b+ 根号 2b=17 - 4根号2,a+b的值 -
向姬肥18486147452 ______ a^2+2b+ 根号 2b=17-4根号2移项得a^2+2b-17=-根号2b-4根号2a^2+2b-17=-根号2(b+4)因为a,b为有理数,所以方程左边为有理数而方程右边有根号2,要使方程成...

闾妻哄3658已知a+b+c=1,求证(1/a)+(1/b)+(1/c)≥9 -
向姬肥18486147452 ______[答案] 证明:∵a+b+c=1∴1/a+1/b+1/c=(a+b+c)/a+(a+b+c)/b+(a+b+c)/c=1+b/a+c/a+a/b+1+c/b+a/c+b/c+1=3+(b/a+a/b)+(c/a+a/c)+(b/c+c/b)≥3+2+2+2=9 (b/a+a/b≥2,c/a+a/c...

闾妻哄3658△ABC内接于单位圆,则(a+b+c)/(sinA+sinB+sinC)=? 要有过程啊 -
向姬肥18486147452 ______[答案] a/2R=sinA. (a+b+c)/(sinA+sinB+sinC)=(a+b+c)/[(a+b+c)/2R]=2R R为圆半径

闾妻哄3658It+be+形容词+for sb+to do It+be+形容词+of sb+to do 怎么区分呢? -
向姬肥18486147452 ______ 两者的区别体现在其中形容词的修饰对象上,可以此区分. 1.It is+adj+of sb+to do sth 中形容词(adj)修饰的是人(sb),侧重表示的是这个人的品质. 例子:it' is kind of you to help me.意思是你能帮我太好了. 其中kind可以翻译为善良的,好...

闾妻哄3658make sb +形容词 -
向姬肥18486147452 ______ make sb+形容词 后面可以跟形容词原级或则比较级,这要看句子的情况了 make it +adj /n + (for sb) to do sth / that cl- / wh – 例如:He made it interesting for us to learn. 还有make me happy等 make后也可以跟形容词比较级 例如:make ...

闾妻哄3658subject+verb+adverbials 是什么句型 麻烦给出5个例句 was she walking home from school taht day?she wasnt walking home from schoo.是什么句型 麻烦给出5... -
向姬肥18486147452 ______[答案] He was hanging about on the street, with his jacket in his hand. All the people were looking at the girl where there were many policemen standing by. He was working hard on his studies,while his meal put on the table. The students went out of school, ...

闾妻哄3658已知a+b=b+c=c+a=5,则a+b+c= -
向姬肥18486147452 ______[答案] a+b=b+c=c+a 所以a=b=c=5/2 a+b+c=15/2