A few math problems with absolute values and positive and negative numbers

Question 1 y|1 so y+1 0 |y+1|=y+1

x|≤1，|y|1 SO2y-x-4 0 SO|2y-x-4|=x-2y+4

In this case m=|x+y|+x-y+5

When x+y 0, m=2x+5 x takes 1 as the maximum value of 7 and as -1 when the minimum value is 3

When x+y 0 m=5-2y y y takes -1 when the maximum value is 7 and 1 when 3

To sum up, the maximum value is 7 and the minimum value is 3

Question 2 a 0, ab 0 so b 0 so a-b-3 0 4+b-a 0

So |a-b-3|-|4+b-a|=b-a+3-4-b+a=-1

Question 3 t1 |t1|+t2/|t2|+t3/|t3|=1 There is only one case 1+1-1=1

So 2 in a, b, c is positive and one negative.

So ABC is negative.

So |t1t2t3|/t1t2t3=-1

Question 4 ABC 0 2 situations 2 negative and positive or 3 positive.

Because a+b+c=0

So (b+c) |a|+(c+a)/|b|+(a+b)/|c|=-（a/|a|+b|b|+c|c|)

Equal to 1 or -3

Positive and negative numbers can be explained by real-life quantities that have opposite meanings.

1. If +8 yuan is counted as income of 8 yuan before mountain liquid, then -6 yuan means 2. 789 meters above sea level is counted as +789 meters, then -789 meters means 3. A decrease of 60 kg is counted as -60 kg, then +80 kg means 4. The year 2008 is recorded as +2008, then -20 years means 2. The amount of opposite meaning in real life can be expressed as positive and negative numbers.

1. minus 15, which is expressed as the temperature of 4 lower than o is 2, positive means westward, then negative is expressed as

3. If the grain output increases by 11%, it is recorded as +11%, and the decrease in production by 6% should be recorded as 4. The temperature at 11 noon on a certain day is 11, and the temperature at 6 o'clock in the morning is 7 lower than 11 o'clock at noon, then the temperature at 6 o'clock in the morning is 13 lower than 11 o'clock in the morning If the temperature at 4 o'clock in the morning is 13 lower than 11 o'clock at noon, the temperature at 4 o'clock in the morning is

Exercise 1 (Level B).

1) Calculation Questions:

7) (8) (b) Calculate by simple method:

3) Known: x=+17(3 4), y=-9(5 11), z=, find: (-x)+(y)+z.

Exercise 2 (Level B) 1) Calculation:

3)|62616964757a686964616fe59b9ee7ad9431333262373862(

b) If|a|=4,|b|=2, and |a+b|=a+b, find the value of a-b.

Exercise 3 (Level A).

a) Multiple choice questions:

1) The correct pronunciation of Eq. -40-28+19-24+32 is ( ).

a) minus 40, minus 28, plus 19, minus 24 and 32 sum (b) minus 40 minus 28 plus 19 minus minus 24 plus 32 (c) minus 40 minus 28 plus 19 minus 24 plus 32 (d) minus 40 minus 28 plus 19 minus 24 minus 32

2) If there is a rational number a+b+c<0, then ( ).

a) At least two of the three numbers are negative, (b) There is only one negative number in the three numbers, (c) At least one of the three numbers is negative, (d) Two of the three numbers are positive, or two of the three numbers are negative.

3) If m < 0, then the absolute value of the difference between m and its opposite number is ( ).

a)0 (b)m (c)2m (d)-2m

4) In the following equations, the value of x-y-z is not equal to ( ).

a)x-(y-z) (b)x-(y+z) (c)(x-y)+(z) (d)(-y)+(x-z)

Exercise IV (Level B).

1) Calculation Questions:

b) Calculate by easy method:

3) When a=-4, b=-3, c=-2, d=-1, find the value of the algebraic formula (ab+cd) (ab-cd).

d) Known 1 + 2 + 3 + ...31 + 32 + 33 = 17 * 33, calculate the following formula.

1-3+2-6+3-9-12+..31-93+32-96+33-99.

Practice Five (Level A).

a) Multiple choice questions:

1) It is known that a and b are two rational numbers, and if their quotient a b=0, then ( ).

a) a=0 and b≠0 (b) a=0 (c) a=0 or b=0 (d) a=0 or b≠0

2) the following four groups are given the numbers 1 and 1; -1 and -1; 0 and 0; -2 3 and -3 2, where the reciprocal is ( ).

a) only (b) only (c) only (d) both.

3) If a |b|(b≠0) is a positive integer, then ( ).

a)|b|is the divisor of a (b)|b|is a multiple of a (c) a and b have the same sign (d) a and b have a different sign.

4) If a>b, then there must be ( ).

a)a+b>a (b)a-b>a (c)2a>ab (d)a/b>1

Best answer: Calculation of positive and negative numbers + (28) = 21

Solution: Original formula = -72 + 37 + 22-17

Solution: Original formula = -16 + 12 - 24 + 18

Solution: Original = 23 + 76 - 36 + 105

Solution: Original formula = -32 + 27 + 72-87

4.A submarine rose 9 meters from 27 meters below sea level to 18 meters below sea level.

Calculation: 1/1) =

1 out of 1) + 1 out of 6 = 49 out of 60

3/3 - (-5/6) + 2/3 cannot be understood.

1/3 + (-1/5) + 1 + 2/3 =

1 out of 1)-(1 out of 1 =.)

8) - (15) + (9) - (12) = 10 - 2/3 + (1/6 of -6) - (1/4) - 1/2 = -3/15 of 12 - 3/2 + (11/4 of -4) + 13/4 = 7 + (-2).

2/2) = 31 + (-5 out of 4) +

7 - (-1/2)+

49 - (3 parts = 69.)

6/5)-7-(

A: 3:00 a.m. on September 1

B: 9:00 a.m. on September 1

C: 22:00 on August 31

A: 3:00 a.m. on September 1

B: 9:00 a.m. on September 1

C: 22:00 on August 31

Because -5, +1, -10 here represent the time difference with Beijing, correspondingly, on the basis of Beijing time, -5, +1, -10 to get the time of these three locations.

1) The 9th number is 1 (9*10) = 1 90

The 14th digit is -1 (14*15) = -1 210

2) The nth number is (n+1) to the power of (-1) * 1 (n*(n+1)).

Hehe. I've done it before, but I forgot it, and now I'm a sophomore in junior high school.

1.9th 1 90

14th -1 210

If n is a composite number, the old number is preceded by "-".

1/(1*2),-1/(2*3),1/(3*4),-1/(4*5)..

So the 9th du9 number.

is zhi1 (9*10)=1 90;

The 14th number is -1 (14*15)=-1 210, so the law is (-1) dao(n+1) (n*(n+1)), that is, (-1) to the power n+1.

Divide by (n*(n+1)) genus.

Nucleus +1

Electron-1 physics stipulates that, as our teacher said, if you precede this phenomenon, you can say that electrons are positively charged and nuclei are negatively charged.

I'm sorry, landlord, you haven't been to the third year of junior high school physics (the people's education version, the Shanghai science version is the second year of junior high school) and chemistry, this reason is hard to say, my answer is the same as the upstairs.

a, e.g. a=-2, then the absolute value of -2 is 2

It's the opposite of a, minus a!

Following the route, it can be seen that it is an alternation of one negative and one positive.

By pressing the direction of the arrow, you can see that downward corresponds to a positive number, right corresponds to a negative number, upward corresponds to a positive number, and rightward corresponds to a negative number.

From this, we can see that: 1) a is a positive number.

2) Positive numbers are placed at a c.

3) In a group of 4, you can see that every four numbers will appear with the same number of symbols as the first four numbers, so:

2014/4=503...2, the 2014th number corresponds to the second number, so it is a positive number, and it is in the position of c.

is a positive number.

Ranked at: a, c.

So in the position of c,

1 x=3,y=1 2, so 4x-2y=112 -b>0,a-b<0,a<-b3 64 a,b,b,a=b;

a, b heterogeneous signs, each other is the opposite number.

1。 12

Greater than-b is greater than a

a is equal to b or a is the opposite of b.

1 Solution: Because: |x-3|+|2y-1|=0So:|x-3|=0 x=3

2y-1|=0 y=2/1

So: 4x-2y=11

2 Solution: Because: a<0 |-b|<|a|-c=-b so: a=0

So: when||x-2|=0 minimum.

So: the minimum is 6

4 Solution: When a b has the same sign, a=b

When a and b have the same sign, a and b are inverse numbers to each other.