Two times of a number minus two fifths to get eight fifths. What's the number

Two times of a number minus two fifths to get eight fifths. What's the number

Let this number be X
2x-2 / 5 = 8 / 5
2X = 8 / 5 + 2 / 5
2x＝2
x＝1

3 / 4 of a number minus 2 / 5 of it, the difference is 7 / 8, find the number

This number is X
3/4x-2/5x=7/8
15/20x-8/20x=7/8
7/20x=7/8
x=5/2

A number minus 35 is exactly 67. What's the number? (solved by equation)

Let xx-35x = 67 & nbsp; 25X = 67 & nbsp; X = 67 × 52 & nbsp; X = 157 = 217 A: this number is 217

A number 1.5 times less than a number is 8. What is the number? (use equation)

Let this number be X
1.5X-1/4=8
The solution is x = 33 / 6
So this number is 33 / 6

The sum of three consecutive odd numbers is 15 times more than the sum of two even numbers between them

Let the middle odd number be X
(X-2)+X+(X+2)-15=(X-1)+(X+1)
The solution is x = 15
Three odd numbers are 13, 15, 17

If the square of the equation x + 2 (m-1) + 4m has two real roots, and the two roots are reciprocal, then the value of M is

If the equation x square + 2 (m-1) x + 4m square = 0 has two real roots, then
4(m-1)²-4m²>0
The solution is m

20.01 tons = () kg
34 yuan = () yuan () jiao () min

20.01t = 20010kg
34 yuan = 2 yuan 3 jiao 4 Fen

99 square is calculated by complete square

（100-1）^2=10000+1-200=9801

If y = (MX ^ 2 + 4 √ 3x + n) / (x ^ 2 + 1) (M

Y = (MX ^ 2 + 4 √ 3x + n) / (x ^ 2 + 1) (M-Y) x ^ 2 + 4 √ 3x + n-y = 0, the discriminant △≥ 0 for the equation with unknown number x, i.e. (4 √ 3) ^ 2-4 (M-Y) * (n-y) ≥ 0y ^ 2 - (M + n) y + Mn-12 ≤ 0 [M + n - √ (m ^ 2 + n ^ 2-2mn + 48)] / 2 ≤ y ≤ [M + N + √ (m ^ 2 + n ^ 2-2mn + 48)] / 2 known y = (MX ^ 2 + 4 √ 3x + n) / (x ^ 2 +

The area of a sports ground is about 2000 square meters______ This is a sports field with an area of about 1 square kilometer

1 square kilometer = 1000000 square meters, 1000000 ／ 2000 = 500. Answer: there are 500 such sports fields, with an area of about 1 square kilometer. So the answer is: 500