If the sum of two rational numbers is zero and the product is zero, then the two rational numbers () At least one of a is zero B both numbers are zero C doesn't have to be all zero D. none of the above is true It is known that the product of two numbers is - 1, one of which is 1.2 and the other is () The product of all integers whose absolute value is not greater than 4 is () If a and 3b are reciprocal, then - 9ab = () 1. It is known that the product of two numbers is - 1, one of which is 1. The other is () 2. The product of all integers whose absolute value is not greater than 4 is () 3. If a and 3b are reciprocal, then - 9ab = ()

If the sum of two rational numbers is zero and the product is zero, then the two rational numbers () At least one of a is zero B both numbers are zero C doesn't have to be all zero D. none of the above is true It is known that the product of two numbers is - 1, one of which is 1.2 and the other is () The product of all integers whose absolute value is not greater than 4 is () If a and 3b are reciprocal, then - 9ab = () 1. It is known that the product of two numbers is - 1, one of which is 1. The other is () 2. The product of all integers whose absolute value is not greater than 4 is () 3. If a and 3b are reciprocal, then - 9ab = ()

1、 B both numbers are zero
a+b=0,ab=0
a*(-a)=0,a=0；
Similarly, B = 0
1. It is known that the product of two numbers is - 1, one of which is 1.2 and the other is
-1/1.2=-5/6
2. The product of all integers whose absolute value is not greater than 4 is 0
Because integers between - 4 and 4 contain 0
3. If a and 3b are reciprocal, then - 9ab = (- 3)
a=1/(3b)
-9ab=-9*1/(3b)*b=-3

If the sum of two rational numbers is greater than zero, then
A: Two rational numbers must be integers
B: Two rational numbers are one positive and one negative
C: Two rational numbers cannot be negative
D: Both rational numbers may be zero
Let's talk about the significance of practice

Let a and B be rational numbers with a + b > 0, so at least one of them is positive

As shown in the figure, AB is a rational number and represents - A-B on the number axis_____ a_____ 0_____ b_____
The size of - a-bab was compared

Hello
According to your chart, I think ab should be the opposite number
-a-b=a+b=0
Good luck

The remainder of 210 divided by 20 is (); the remainder of 0.8 divided by 0.3 is ()

10 0.2

Thirty percent of the number a is equal to forty percent of the number B. what percentage of the number a is and what percentage of the number B is

30% of the number a is equal to 40% of the number B. the number a is 4 / 3 of the number B and the number B is 3 / 4 of the number a

How many pages does a story book have? How many pages do you read every day?

Reading days: (10 + 8) / (6-4) = 9
Number of pages: 4 × 9 + 10 = 46 or 6 × 9-846

1/【(1/4-0.05)*5/8】 【3/4÷（1/4+5/8）】÷（1-1/2） 【2-（5/3-1.5）*12/17】÷8/51
【3/4÷（1/4+5/8）】÷（1-1/3）
Recursive equation calculation, ask everyone, urgent

1/【(1/4-0.05)*5/8】
=1/【0.2*5/8】
=1/（1/8）
=8
【3/4÷（1/4+5/8）】÷（1-1/2）
=6/7÷1/2
=12/7
【2-（5/3-1.5）*12/17】÷8/51
=(2-(5/3-1.5)*12/17)/(8/51)
= 12

Divide the 8 meter long rope into 5 parts, each part is a fraction of 8 meters, each part is a fraction of 1 meter, each part is a fraction of several meters
That is to say, a fraction of 8 meters is equal to a fraction of 1 meter

Divide the 8-meter-long rope into 5 parts, each part is 1 / 5 of 8 meters, each part is 8 / 5 of 1 meter, each part is 8 / 5 of 5 meters
That is to say, 1 / 5 of 8 meters and 8 / 5 of 1 meter are equal

(3) F (x) is a quadratic function, and f (0) = - 5, its maximum is 4. For any x ∈ R, if f (2x) = f (6-2x), then f (x)=

Let f (x) = ax ^ 2 + BX + CF (0) = 5C = 5 (4ac-b ^ 2) / 4A = 44ac-b ^ 2 = 16a4ac-16a = B ^ 24a (C-4) = B ^ 2A = B ^ 2 / [4 (C-4)] = B ^ 2 / 44ax ^ 2 + 2bx = a (6-2x) ^ 2 + B (6-2x) 4ax ^ 2 + 2bx = 4ax ^ 2-24ax + 36a + 6b-2bx2bx = - 6B ^ 2x + 9b ^ 2 + 6b-2bx4bx = 3B ^ 2 + 6b4x = 3B + 6x = (3b + 6) / 4

A project is completed by team a and team B. It takes 16 days for team a to complete it alone and 12 days for team B to complete it alone. Team a will do it for 3 days first, and then the two teams will cooperate. Q: how many days can we complete 11 / 12 of all the work

Set up another X days
3*1/16+x(1/16+1/12)=11/12
The solution is x = 5