Look at the following column of numbers to find out the law: minus half, two thirds, three quarters, four fifths, six fifths, seven sixths Write the number of items 7, 8 and 9 What is the number 2014? Question (3) if this column of numbers is arranged infinitely, which two numbers are closer to each other?

(1)-7/8 8/9 -9/10
(2)2014/2015
(3) 1 and - 1

In the football round robin, team a wins Team B 4:1, team B wins team C 2:1, and team C wins team a 1:0. Try to calculate the number of net goals of each team, and determine the ranking order of team a, B and C according to the number of net goals

A 4-1-1 = 2, B 1-4 + 1 = - 2, C NO (0)
A1
C 2
B 3

The limit of 2x / (x ^ 3-3) when x tends to 1

-4

Simplification ratio 68:17 18:54
68：17 18：54

68：17= （68÷17）：（17÷17）=4:1
18：54=（18÷18）：（54÷18）=1 ：3

Factorization of 25A ^ 2-100b ^ 2

55 * 102-110 simple algorithm

55*102-110
=110*51-110
=110*(51-1)
=110*50
=5500

If the circle C (x-3) square + (Y-1) square = 9 and the line X-Y + a = 0 intersect with two points a and B, and OA is perpendicular to ob, calculate the value of A

Delta OAB is an isosceles right triangle
Then the distance from O to the straight line is √ 2 / 2 times of the radius
List the formula for the distance between a point and a line
d=｜（3-1+A）｜/√2=3×√2/2
The solution is: a = 1 or - 5

Solving the equation: 3 / 5x + x = 20 I know x is 12.5

3/5X+X=20
3x+5x=100
8x=100
x=100/8
x=12.5

If the equation a2x2 + (a + 2) Y2 + 2aX + a = 0 represents a circle, then the value of a is ()
A. A = 1 or a = - 2b. A = 2 or a = - 1C. A = - 1D. A = 2

If the equation a2x2 + (a + 2) Y2 + 2aX + a = 0 represents a circle, then A2 = a + 2 ≠ 0 (2AA + 2) 2 − 4AA + 2 > 0, the solution is a = - 1

The number (98 + 147) / 49 calculated by simple method

=98/49+147/49
=2+3
=5