How to compare the size of 12 out of 28, 45 out of 54, 40 out of 56? How to compare the size of 15 out of 27, 45 out of 99, 49 out of 63?

How to compare the size of 12 out of 28, 45 out of 54, 40 out of 56? How to compare the size of 15 out of 27, 45 out of 99, 49 out of 63?

How to compare the size of 12 out of 28, 45 out of 54 and 40 out of 56?
12 out of 28 = 24 / 56
45 out of 54 = 45 / 54
40 out of 56 = 40 / 56
45 out of 54 ＞ 40 out of 56 ＞ 12 out of 28
How can 15 out of 27, 45 out of 99 and 49 out of 63 compare?
15 out of 27 = 15 / 27 = 5 / 9
45 out of 99 = 45 / 99 = 5 / 11
49 out of 63 = 7 / 9
They are 49 out of 63, 15 out of 27 and 45 out of 99
If the denominator is the same, the fractional value of the large numerator is larger and the fractional value of the small numerator is smaller
If the numerator is the same, the fractional value with larger denominator is smaller, and the fractional value with smaller denominator is larger

Solving exponential equation: (1) 8 ^ X-1 degree = 3 ^ x (2) 2 ^ 2x-2 ^ x = 56, please write the details

8^x/8 = 3^x → (8/3)^x = 8→ x = log(8/3) 8
2 ^ 2x = (2 ^ x) ^ 2 let t = 2 ^ x
T ^ 2-t-56 = 0; t = 8 or T = - 7 (discard); so x = 3

How to solve the equation of (10000-x) × 0:015-0:2x = 145:56
It's 146:56

(10000-x)×0.015－0.2x＝146.56
150-0.015x-0.2x=146.56
-0.215x=-3.44
x=3.44/0.215=16

Cube of 2x - cube of x = 56

(2x) cube-x cube = 8 x cube-x cube = 7 x cube = 56
So the cube of x = 8
So x = 2