The square of (x-y) = 12 (x+y) = 16 to find xy.
The square of (x-a) =x square +x+0.25. Find the square of (2a- 10.
X+y=3 xy=- 12 x +y =？
(x-y) squared =?
2 Party A and Party B are running on a square track with a side length of 100m; They start counterclockwise from two adjacent vertices (A is in front of B). A runs 250 meters per minute, and B runs 2 10 meters per minute. How long does it take for A and B to run on the same side after starting?
Xiaoming is in the street. Every six minutes, a 1 bus comes head-on, and every 12 minutes, a 1 bus passes him from behind. If every car has the same speed and the same departure interval, then there will be a bus every few minutes from the starting point.
Q: The salt content ratio of brine A and brine B is 2:3, the water content ratio is 1:2, and the weight ratio of brine is 40:77. What is the concentration of brine A?
Q: The salt content ratio of brine A and brine B is 2:3, the water content ratio is 1:2, and the weight ratio of brine is 40:77. What is the concentration of brine A?
6 When the degrees of the inner angles of a polygon are arranged from small to large, the same degree increases at one time, with the maximum angle 140 and the minimum angle 100. How many sides of the polygon do you want?
7 Triangle ABC, O is any point on high AD near BC, connecting CO and extending intersection AB to point E, connecting BO and extending intersection AC to point F, and connecting ED and FD. Proof: angle EDB= angle FDC.
8. A rectangular wasteland was opened in a certain place, and a new park with the theme of environmental protection was built. It is known that this wasteland is three times as long as it is wide and covers an area of 60,000 square meters. Seek the length and width of the park. (accurate to 1 meter).
9. Li Sijia bought Xiaoying a spherical gift with a volume of 4 100 cubic centimeter. There are three cubic gift boxes for her to choose from:15cm×15cm×15cm; 20 cm× 20 cm× 20 cm; 40 cm x 40 cm x 40 cm. The bigger the box, the higher the price. What kind of packing box is suitable for Li Sijia?
10 One or two trucks drive from place A to place B at a constant speed, leaving for 2 hours. A car rear-ended the truck from A. The car was 30 kilometers faster than the truck, but it suddenly broke down after driving for an hour. After repairing 15 minutes, it caught up with the truck on the road again, but the speed decreased 1/3. It took another two hours to catch up with the van.
1 17 oil drums (as shown in the figure) contain three different liquids, that is, liquid A has only 1 drum, and the total capacity of liquid B is three times that of liquid C. Please write down the liquid in each drum on the horizontal line below and write down the disintegration process side by side. The following brackets indicate the capacity of each barrel (12, 14, 15, 17, 20, 25, 28).
12 Given (m+n)*(m+n)+|m|=m, |2m-n-2|=0, find the value of mn.
13 known integers x, y and z satisfy x ≤ y.
14 it is known that the equations about x and y are1ax+2y =1+a22x+2 (a-1) y = 3. When a is a value, the equation is 1. There is only one solution. 2. There is no solution. 3. There are infinite groups of solutions.
15 If all the solutions of the equation 1xx+Ky = K2x-2Y = 1 are integers, what integer value should K take?