The fourth question (1) is missing, so it doesn't count!

(2) x =12/113x =1652x4/13 (note: x in the answer is a multiplication sign).

(3)①(24x 38-2 15)÷60% = 1 16x 1/6

②2 12÷ 14-3 13x 125 =-39 109 X6/7

(4) If you can't see the picture, you can't!

Fifth, apply the principle of "the shortest line segment between two points"

Connect the east village directly with water pipes.

(1) 4-(120 ÷ 8 ÷ 5) =1.

⑵(2520-9x 120)÷ 10 = 144

⑶28÷(54-47)=4 4+8= 12, so when we met, it was 12: 30.

⑷48÷75%-( 1-40%)=320

⑸ 1- 12x( 1/20+ 1/40)÷ 1/20 = 2

7. Teachers are the most direct organizers of the teaching process. The leading role of teachers and the directional development of teaching process depend on teachers' organization of teaching activities, which mainly includes two aspects: ① teachers organize teaching and learning processes in a planned way according to the systematic planning of teaching activities, so as to promote the improvement and perfection of students' self-organization function of autonomous learning activities; Pay attention to the cultivation and formation of students' self-organization ability in the learning process, and constantly improve the self-organization degree of learning activities through guidance and encouragement.