Simplify the problem solving process of | M-3 | - | 1-m | Such as the title, to discuss the classification

Simplify the problem solving process of | M-3 | - | 1-m | Such as the title, to discuss the classification

|m-3|-|1-m|=|m-3|-|m-1|
① When m ≥ 3, M-3 ≥ 0, M-1 ≥ 0, the original formula = M-3 - (m-1) = - 2;
② When 1 ≤ M

1. (3a & # B to the third power) / (- AB to the third power)
2. The fourth power B of (- 6a) & # 178; c) / the third power B of 3A
3. The quintic power of - 12a and the cubic power of B C / (- 3A & # 178; b)

1. (3a & sup2; the third power of B) / (- AB) = (3a ^ 2B ^ 3) / (- AB ^ 3) = - A2. (the fourth power of-6a B & sup2; c) / the third power of 3A B = (- 6A ^ 4B ^ 2C) / (3a ^ 3b) = - 2abc3. The fifth power of-12a C / (- 3A & sup2; b) = - 12a ^ 5B ^ 3C / (- 3A ^ 2b) = 4A ^ 3B ^ 2C

If a × 3 = B × 4 = C × 5, then a: C = (): ()
There should be a clear solution
OK, 100 points!

3a=5c,
a/c=5/3,
a:c=5:3

A mathematical problem: it is known that in RT △ ABC, ∠ C = 90 ° A: B: C = 3:4:5, if C = 25, then a =? B =?

b=c*[4/5]=20
a=c*(3/5)=15