The mathematical principle is that both hunters and soldiers should aim at the target__________ . The three straight lines intersect each other in pairs, and there is no more than one__ There are at least two intersections__ There are two intersections

The mathematical principle is that both hunters and soldiers should aim at the target__________ . The three straight lines intersect each other in pairs, and there is no more than one__ There are at least two intersections__ There are two intersections

Basic mathematical principle: two points determine a straight line
When the target center is accurately located in the notch and the collimator is on the straight line, it hits the 10 rings
Three straight lines intersect each other, there are at most three intersections and at least one intersection

1.[12-6y+( )]-[-5y^2-( )+( )]=2y^2+3y-4
2. Given x ^ 2-xy = 8, xy-y ^ 2 = 3, then x ^ 2-y = (), x ^ 2-y ^ 2 = ()
a^3+a-4-( )=a^3-a^2+a

I just filled it in!
(1)[12-6y+(-3y^2)]-[-5y^2-(9y)+(16)]=2y^2+3y-4
(2)x^2-y^2=11
In general, the answer to question 1 is - 3Y ^ 2 9y 16
The second question is 11

1. Known a

2b-2a
-4ab

1. If | a | = - A, then 2A must be ()
2. If a + B0, B. A, B are positive and negative, and the absolute value of positive number is greater than that of negative number
C.a

|A | must > = 0, so - a must also > = 0, then a

Half by eight is one by four, and the equation is changed to be proportional

1 / 2 * 8 = 1 * 4 1 / 2:1 = 4:8, i.e. 1:2 = 4:8 or 1 / 2:4 = 1:8

Solving the quadratic equation 2x-5y = 10 3x-10y = 5
Be clear

Y = 4, x = 15, hope to adopt

There are 72 cases of beverage and mineral water in the food store. The number of cases of mineral water is 4 / 5 of that of beverage. How many cases of beverage and mineral water are there
Use 4 cm, 6 cm pieces of paper to place a square. How long is the side of the square? How many squares do you need at least?

72÷9=8
8 × 4 = 32 mineral water
72-32=40

Finding the positive integer solution of the equation x = 2Y + 8 / y + 1
Another problem: the integer solution of Qiu's equation yx-12 = x + 3Y
Positive integer solution of equation x = (2Y + 8) / (y + 1)

X = 2Y + 8 / y + 1 solution method: because it is a positive integer, y can only bring in 8 / y = integer numbers can only bring in 8 42105 numbers, but the denominator is not 0 can only bring in 8 421 four numbers, x value you bring in the calculation
1 11
2 9
4 11
8 18

We bought hamburgers and chips and drinks

We bought hamburgers,French fries and beverages.

9 / 20-5 / 12 = 1 / 30, how do you calculate it?

9/20-5/12=27/60-25/60=2/60=1/30