Ask for the answer to the question of the first year of junior high school, and ask for the answer t

1) x is less than 0, so the absolute value of x is -x, because the absolute value of a negative number is its opposite. The absolute value of -x is -x. Because x is negative, -x is positive.

The absolute value of a positive number is itself. So the absolute value of -x is still -x. Therefore, the absolute value of x minus -x is -x-(-x)=-x+x=0, so the answer is b.

2) x=3, then the absolute value of x-1 is the absolute value of 2, the absolute value of 2 is 2 (very simple) The absolute value of x+4 is the absolute value of 7, and the absolute value of 7 is still 7. Therefore, the absolute value of x-1 + the absolute value of x+4 is equal to 2+7=9. The answer is 9

3) If you can't figure it out, the calculator can do it. The answer is 12.

4)(-20)+(3)-(5)-(7): The parentheses are -20+3+5-7=-19(Again, a calculator will do the trick.) The answer is -19.

In the first question, d is selected if it is the absolute value of the whole, and b is selected if it is the absolute value of negative x

II, 7III, 12

IV ,-19

You should do such a simple question by yourself.

2(x+1)-x

2x+2-x

x+22a²+4a²

2a²2xy+3xy=5xy

4.Write a similar term with the highest order in a+ab+b+1: (ab) 5Merge similar terms: 2a-3(a-b+c) = -a+3(b-c).

2.-2a quadratic + 4a quadratic = (-2a) 2 + (4a) 2 = 4a 2 + 16a 2 = 20a 2

4.Write a similar term with the highest order in a+ab+b+1: (the highest term is ab, and the same term can be 2ab).

5.Combine similar terms: 2a-3(a-b+c)=2a-3a+3b-3c=-a+3b-3c

1.Let's assume that the total price of the book is x. Then (original price - discounted ** = saved**) x = 60

60-12 = 48 48 + 20 = 68 yuan lead sedan (48 is the money paid after the discount, 20 is the price of the preferential card).

2.(1) Suppose the original price of the clothes is $x. Then the profitable one is (1 + x=108 The loss is ( x=180 Original price** =180+108=288 Now**=135+135=270 288 270 Loss, loss of 18 yuan.

2) As long as A is a positive integer, then the vendor has been losing money.

3.(1) 134 + 466 = 600 yuan.

2) 134 + (466-466 10) = yuan.

3) Yes, because 134+466=600 600-100=500 500 100 450+80=530

530 so more saving.

So good, didn't you add ?

3x+2x=2-x as defined by

6x = 2x = 2/6

x = 1/3

14 questions. Set the screws with x people, and use the nuts with y people.

Equations. x＋y＝22

2 (1200 times x) 2000y

Solve systems of equations. 15 questions.

A hour to complete 1 20

B one hour to complete 1 12

1 minus 4 times 1 20 equals 16 20

This is the rest of the work after 4 hours of A.

16 20 divided by parentheses (1 20 1 12) equals 6

I used to do this question in school, but it's been several years, and now I forget it.