9.
如图,已知直线AB∥CD,点E,F分别在直线AB和CD上,EH平分∠AEN,EN∥MF,HE∥FN.若∠N=114°,则∠MFH的度数为( )
| A. | 48° | B. | 58° | C. | 66° | D. | 68° |
8.若$\left\{\begin{array}{l}{x=-3}\\{y=2}\end{array}\right.$是关于x,y的方程组$\left\{\begin{array}{l}{4x+y=a}\\{bx-2y=2}\end{array}\right.$的解,则a+b的值为( )
| A. | 8 | B. | -8 | C. | 12 | D. | -12 |
6.下列各对数中,是二元一次方程3x-y=-7的解的是( )
| A. | $\left\{\begin{array}{l}{x=1}\\{y=4}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{x=2}\\{y=3}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{x=-1}\\{y=4}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{x=-2}\\{y=-3}\end{array}\right.$ |
5.蔬菜经营户老王,近两天经营的是青菜和西兰花.
(1)昨天的青菜和西兰花的进价和售价如表,老王用600元批发青菜和西兰花共200市斤,当天售完后老王一共能赚多少元钱?
(2)今天因进价不变,老王仍用600元批发青菜和西兰花共200市斤.但在运输中青菜损坏了10%,而西兰花没有损坏仍按昨天的售价销售,要想当天售完后所赚的钱不少于昨天所赚的钱,请你帮老王计算,应怎样给青菜定售价?(精确到0.1元)
0 285539 285547 285553 285557 285563 285565 285569 285575 285577 285583 285589 285593 285595 285599 285605 285607 285613 285617 285619 285623 285625 285629 285631 285633 285634 285635 285637 285638 285639 285641 285643 285647 285649 285653 285655 285659 285665 285667 285673 285677 285679 285683 285689 285695 285697 285703 285707 285709 285715 285719 285725 285733 366461
(1)昨天的青菜和西兰花的进价和售价如表,老王用600元批发青菜和西兰花共200市斤,当天售完后老王一共能赚多少元钱?
| 青菜 | 西兰花 | |
| 进价(元/市斤) | 2.8 | 3.2 |
| 售价(元/市斤) | 4 | 4.5 |