Inequality X / 2 + X / 6 + X / 12 + ··· + X / 9900

Inequality X / 2 + X / 6 + X / 12 + ··· + X / 9900

Left = x (1 / (1 × 2) + 1 / (2 × 3) + 1 / (3 × 4) +. 1 / (99 × 100))
=x(1-1／2+1／2-1／3+1／3-1／4+.+1／99-1／100)
=x(1-1／100).
99x ＜ 2x + 5, 1.01x ＞ - 5, X ＞ 500 / 101

Finding inequality 6

Finding inequality 6

/(9-x)!>6*6!/(6-x+2)!

9!*(8-x)!>6*6!*(9-x)!
9*8*7>6*(9-x)
84>9-x
x>-75

The sum of three numbers a, B and C is 300. It is known that the number a is 50 larger than the number B, and the number B is 20 larger than the number C. what is the number a

Let a, B and C be x, y and Z respectively
x+y+z=300
x-y=50
y-z=20
The solution is x = 140, y = 90, z = 70
The number of a is 140

The equation 3 / x + 3-2 / 5-x = 6 / X-1, the result is obtained by removing the denominator

3 x + 3-2 5-x = 6 X-1,
The result obtained by removing the denominator
2x+6-15+3x=x-1
If we move items and merge similar items, we get 4x = 8
x=2

The number a is one fifth more than the number B. what's the number B?

Let B be X
x(1+1/5)=120
x=150

a. B is a positive number, ab = 4, find the minimum of 2A + 3B
(2a + 3b) ^ 2 = (2a) ^ 2 + (3b) ^ 2 + 12ab > = 2 * 2A * 3B + 12ab = 96, just like how to do this step!

a. So, 2A + 3B > 0 (X-Y) ^ 2 > = 0 so x ^ 2 + y ^ 2-2xy > = 0 so x ^ 2 + y ^ 2 > XY; 2A + 3B = (follow sign 2a) ^ 2 + (follow sign 3b) ^ 2 > = 2 * (follow sign 2A * follow sign 3b) = 2 * (follow sign 6ab) = 2 * (follow sign 24) = 2 * 2 * (follow sign 6) = 4 * (follow sign 6) so, the minimum value of 2A + 3b is 4 * (follow sign 6)

4 / 5 of the number a is equal to 1 / 2 of the number B

Because four fifths of a is half of B, B is eight fifths of a, and a is five eighths of B. A is three fifths more than B, that is 60%

Let a be a 86 matrix whose rank is known to be 4, then the dimension of solution space of homogeneous linear equations with a as coefficient matrix is?

If the rank of matrix A of order m × n is R (a), then the dimension of solution space of AX = 0 is N-R (a). So the dimension of solution space of this problem is 6-4 = 2

A, B and C jointly process 120 parts. The number of parts processed by a is 1 / 3 of the total number of B and C, and the number of parts processed by B is 1 / 2 of the total number of B and C. how many parts have a, B and C processed?

A: 120 × 1 / (3 + 1) = 30
B: 120 × 1 / (2 + 1) = 40
C processing: 120-30-40 = 50