Xiao Ming read a 120 page story book. On the first day, he read 1 / 6 of the whole book. On the second day, he read 20% more than on the first day How many pages did you read the next day

Xiao Ming read a 120 page story book. On the first day, he read 1 / 6 of the whole book. On the second day, he read 20% more than on the first day How many pages did you read the next day

I read it on the first day
120 × 1 / 6 = 20 (page)
I read it the next day
20 × (1 + 20%) = 24 (pages)
Comprehensive
120×1/6×（1+20%）
=20×1.2
=24 (page)
Master to help younger sister do the next 1 Germany 4 math!
1. Known a = 2x ^ 2 + 3xy-2x-1, B = - x ^ 2 + XY-1
(1) find 3A + 6B;
(2) if the value of 3A + 6B has nothing to do with the value of X, find the value of Y
2. According to the requirements, the polynomial x ^ 3y-4xy ^ 2 + 2x ^ 3-x ^ 2y-1
(1) enclose the following two items in the brackets with a "-" sign in front of them;
(2) enclose the cubic items in the brackets with a "-" sign in front of them;
(3) enclose the items with letter Y in the brackets with "+" in front, and the rest in the brackets with "-" in front
3. When calculating "m + n", the nickname mistakenly regards "m + n" as "M-N", and gets the answer of 1 / 2XY YZ + 5xz. If n = 7xy YZ + 3xz, get the correct result
4. It is known that a ＜ - B and a / b ＞ 0, which is simplified as | a | - | B | + | a + B | + | ab |
Please master the process of 1, 3 and 4 in detail! The main process is to be clear! Thank you!
Speed! Online!
My third year, the title is very simple, 1. (1) 3A + 6B = (2x ^ 2 + 3xy-2x-1) * 3 + 6 * (x ^ 2 + XY-1) = 6x ^ 2 + 9xy-6x-3 + 6x ^ 2 + 6xy-6 = 12x ^ 2 + 15xy-6x-9 (2) the title is wrong, the value of 3A + 6B must be related to x, may have nothing to do with y. 2
1. 3A + 6B = 3 (2x ^ 2 + 3xy-2x-1) + 6 (x ^ 2 + XY-1)
=6X^+9XY-6X-3+6X^+6XY-6
=(6X^2+6X^2)+（9XY+6XY）-6X+（-3-6）
=12X^2+15XY-6X-9
2
Because the value of 12x ^ 2 + 15xy-6x-9 has nothing to do with X.
So 15... Unfolds
1. 3A + 6B = 3 (2x ^ 2 + 3xy-2x-1) + 6 (x ^ 2 + XY-1)
=6X^+9XY-6X-3+6X^+6XY-6
=(6X^2+6X^2)+（9XY+6XY）-6X+（-3-6）
=12X^2+15XY-6X-9
2
Because the value of 12x ^ 2 + 15xy-6x-9 has nothing to do with X.
Y = 159-150, so
Y=9/15
2、 The title is not very clear
3、 According to the meaning of the title:
Because. M-N = 1 / 2xy-zy + 5xz, n = 7xy-yz + 3xz, M = (7xy-yz + 3xz) + (1 / 2xy-zy + 5xz) = (7 + 1 / 2) XY + (- yz-zy) + (3xz + 5xz) = 7 / 1 / 2xy-2yz + 8xz
4、 According to the meaning of the title:
Because a ＜ - B and a / b ＞ 0
So | a | - | B | + | a + B | + | ab|
=A-B+A+B+AB
=（A+A）+（-B+B）+AB
=2A+AB
If I'm wrong, don't blame me. I haven't learned it yet. I just read a book. Please tell me more! You don't even know (2) of question 1. You're still Junior 3
! Put it away
Z
I'm a sophomore in junior high school, and my idea is similar to that of junior high school
A mathematical problem has a two digit number, which is five times larger than the sum of its one digit number and ten digit number
Number exchange position, the original number is smaller than the new number by 9 to find two digits
Let the original two digit, ten digit be x and one digit be y
that
10x+y=5(x+y)+2
10x+y-10y-x=-9
You can get it
5x-4y=2
x-y=-1
The solution is as follows
X=6
Y=7
The original answer is 67
It turned out to be 67
Sixty-seven
Xiao Ming read a story book. On the first day, he read one fifth of the whole book. On the second day, he read 20 pages. There are 44 pages left. How many pages are there in this book?
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On the first day, if you read one fifth, you will have four fifths left. From the meaning of the title, you can see that there are (20 + 44 = 64 pages) left. So these 64 pages are the four fifths left
So the total number of pages is 64 divided by four fifths, and the result is 80 pages
simple
But I thought about it for a long time
20+44=64
64 divided by (1-1 / 5)
I'm in sixth grade, too
(20 + 44) / (1-1 / 5) = 80 pages
(20 + 44) \ (1-fifth) = 80 pages
That's 80 pages
The number of books in the library of Dongcun primary school is 60% of that of Mazhuang primary school. The number of books in the library of Mazhuang primary school is 250 more than that of Dongcun primary school?
The number of books in the library of Mazhuang primary school is X
X * (1-60 per cent) = 250
40% x = 250
x=625
625-250 = 375 (volume)
Bonus points!
There are x books in the library of shemazhuang primary school
x-60%x=250
x=625
60%x=375
A: there are 625 books in the library of Mazhuang primary school and 375 books in the library of Dongcun primary school
There are x books in the library of shemazhuang primary school
X-0.6X=250
X=625
So there are 625 books in the library of Mazhuang primary school
The number of books in the library of Dongcun primary school is 625-250 = 375
Dongcun primary school 375 Mazhuang primary school 625
(1-60%) except 250
=625
625x60%=375
Of all the four digits, how many numbers have the sum of the quotient numbers equal to 34?
34 - 9×3 = 7
34 - 9×2 = 16 = 8 + 8
34 - 8×3 = 10
To sum up, if the sum of the numbers equals 34, only
The arrangement of (7,9,9) and (8,8,9,9) can not be any other case
There are 4 + 4 * 3 * 2 * 1 / 2 * 2 = 10 species
79⑨9
⑨7⑨9
9⑨7⑨
9⑨97
⑧8⑨9
⑧9⑧9
⑧9⑨8
98⑧9
9⑧98
⑨9⑧8
Of all the four digits, how many numbers have the sum of the quotient numbers equal to 34
According to the size of 34, the four digits of four digits must be big enough.
Because there are too many sensitive words, I won't list them. It's hard to read sensitive words.
Xiaojun and Xiaoming have 24 storybooks in total. Xiaoming's storybooks are 3 less than their total number of 34. How many storybooks does Xiaoming have?
A: Xiao Ming has 15 storybooks
In a square with a side length of 12.75cm, dig out a square with a side length of 7.25cm, and the area of the remaining part is ()
A. 11cm2B. 20cm2C. 110cm2D. 200cm2
The area of the remaining part is 12.752-7.252 = (12.75 + 7.25) × (12.75-7.25) = 20 × 5.5 = 110 (cm2)
Find the minimum four digits of 34
To write the process, don't use the equation, use the formula, write how to get it at each step
To minimize the number, the highest order must be the smallest, and the rest must be the largest
So fill in 9 from the first place and 7 from the last thousand
Answer 7999
one thousand two hundred and thirty-four
The range of the sum of 4-digit numbers is 1 ≤ x ≤ 369999, which is the largest 4-digit number. Except that the number on the thousand digit must be the smallest, so when the thousand digit is equal to 7 and the sum of the smallest is equal to 34, the rest of the numbers are greater than 7999
To minimize the number, the highest order must be the smallest, and the rest must be the largest
Answer 7999
seven thousand nine hundred and ninety-nine
Because 9999 is the largest four digit number, and the sum of the numbers on all of you is 36
The sum of your numbers is 34. You need to subtract 2 from the top
So it's 7999
Xiaohong, Xiaohua and Xiaogang each have some storybooks. After Xiaohong gave Xiaohua three and Xiaohua gave Xiaogang five, the number of books for the three people was the same. How many more books did Xiaohua have than Xiaogang?
5 × 2 - 3, = 10 - 3, = 7 (copies); a: Xiaohua used to have 7 more copies than Xiaogang