a. Both B and C denote rational numbers which are not equal to 0, and satisfy the following conditions: a + | B + | B + | C| 1) Try to judge the sign of a, B and C (2) Find the value of | ABC | in the formula ABC

a. Both B and C denote rational numbers which are not equal to 0, and satisfy the following conditions: a + | B + | B + | C| 1) Try to judge the sign of a, B and C (2) Find the value of | ABC | in the formula ABC

1/3

If a, B and C are rational numbers which are not equal to 0, then the result of a / | a | + B / | B | + C / | C |, may be equal to 0----------

For a, B, C, there are several cases: 1. Three negative 2. One positive 2 negative 3. Two positive 1 negative 4. Three positive
When the absolute value of a, B, C is equal to - A, - B, - C, then the original formula is equal to (- 1) + (- 1) + (- 1) = - 3
In case 2, if a is positive and the absolute values of a, B and C are equal to a, - B, - C, then the original formula is equal to (1) + (- 1) + (- 1) = - 1
In case 3, let C be negative, and the absolute value of a, B, C is equal to a, B, - C, then the original formula is equal to (1) + (1) + (- 1) = 1
In case 4, the absolute value of a, B, C is equal to a, B, C, then the original formula is equal to (1) + (1) + (1) = 3
So the results of the original formula have four cases, namely - 3, - 1,1,3

2 of 185 × 17 minus 15 of 2 × 17
One more
12 of 2003 × 47 + 2003 △ 47 × 35

185*17/2-2*17/15
185*17/2-17/15*2
185*17/13*2
185*17/26

Solve the equation (m-1) x & # 178; + 2mx + m + 1 = 0 about X

（m-1)X²+2mx+m+1=0
[(m-1) x + (M + 1)] times (x + 1) = 0
(m-1)x+(m+1)=o x+1=0
.
Multiply by a cross

In permutation and combination, why divide the problem of equipartition by factorial
For example: six books are divided equally among three people, and the different methods are C6 (2) * C4 (2) * C2 (2) / 3! Why divide by 3! Please explain for me, thank you

Because in your C6 (2) * C4 (2) * C2 (2), you have arranged all three of them
Add ABCDEF to this book
C6 (2) can be pumped to AB, C4 (2) can also be pumped to C2 (2)
That is to say, they have been fully arranged
And the question is to divide equally, that is, only grouping does not need to be arranged, so divide by 3 again!

The surface area of a 2m long cuboid wood increases by 40dm2 after it is cut into five sections. What is the volume of this wood cubic decimeter?

2 meters = 20 decimeters, 40 △ 8 × 20, = 5 × 20, = 100 (cubic decimeters). A: the volume of this wood is 100 cubic decimeters

Nine inches plus one inch is one foot

If you get an inch, you'll change it from an inch to a ruler

The sum of the first n terms of the arithmetic sequence {an}, {BN} is Sn, TN, Sn / TN = 2n / 3N + 1, then A3 / B5
It's A3 / B5, not anything else

2n/3n+1?2n/(3n+1)?2n/(3n+1):,n=1,a1/b1=1/2,b1=2a1a2=a1+d,b2=b1+c=2a1+c,a2/b2=4/7=(a1+d)/(2a1+c),8a1+4c=7a1+7d,a1=7d-4ca3=a1+2d,b3=b1+2c=2a1+2c,a3/b3=3/5=(a1+2d)/(2a1+2c),6a1+6c=5a1+10d,a1=10d-6c=7d-4c...

One point six to two fifths reduction ratio and ratio

1.6:0.4=4:1

The solution of 100 (1-x) square = 64?