Naughty has a story book. I have read 1 / 5 of this book, read 36 more pages and read 80% of the whole book. How many pages are there in this book?

Naughty has a story book. I have read 1 / 5 of this book, read 36 more pages and read 80% of the whole book. How many pages are there in this book?

Four fifths minus one fifths equals three fifths, 36 divided by three fifths equals 60

There are a number of science and technology books and story books in the bookstore. It is known that two fifths of science and technology books are equal to three fourths of story books. What is the proportion of story books?

There are x story books and Y science and technology trees
Then 2 / 5Y = 3 / 4x
Multiply both sides by 4 / 3 at the same time
So x = 8 / 15
So storybooks are 8 / 15 of the technology tree

A total of 150 story books and science and technology books were delivered to the bookstore, of which story books accounted for 80% of the total,
When some storybooks are sold, they account for 70% of the total. How many storybooks are sold?

50, the original story book is 150 * 80% = 120, set to sell X,
120-X=（150-X）*70%
The solution is x = 50

Simple calculation of 3.8 * 4.1-0.38

3.8*4.1-0.38
=3.8*4.1-3.8*0.1
=3.8*(4.1-0.1)
=3.8*4
=(4-0.2)*4
=4*4-0.2*4
=16-0.8
=15.2

LIM (2-x) ^ 3 (3 + x) ^ 5 / (6-x) ^ 8 x approaches infinity

The highest order of the numerator denominator is 8, so when x tends to infinity, the result is the highest power coefficient of the numerator divided by the highest power coefficient of the denominator,
That is (- 1) * 1 / 1 = - 1

B + AX = 3x when AB satisfies what conditions respectively, the equation has only one solution, and the equation is solved

b+ax=3x =》 b=（3-a）x
When a = 3, B = 0, X can be any real number, that is, the equation has countless streets;
When a! = 3, the equation has unique x = B / (3-A)
Therefore, when a and B satisfy the condition of a! = 3, the equation has only one solution x = B / (3-A)
[a! = 3 means that a is not equal to 3]

1.73 × 1.3 + 0.27 × 1.3-1.3 by simple method

1.73×1.3＋0.27×1.3-1.3
=(1.73+0.27-1)×1.3
=1×1.3
=1.3

When LIM (x tends to 0), how much is (the square of x) multiplied by (cos1 / x)

When LIM (x tends to 0) (the square of x) times (cos1 / x)
=When LIM (x tends to 0) (the square of x) times LIM (x tends to 0) (cos1 / x)
Because LIM (x tends to 0) (the square of x) = 0, it is infinitesimal,
And | LIM (x tends to 0) (cos1 / x)|

Given that the polynomial ax & sup2; + 2bxy + X & sup2; - x-2xy + y of X, y does not contain binomial, find 5a-8b
Given that the polynomial ax & sup2; + 2bxy + X & sup2; - x-2xy + y of X, y does not contain binomial, find 5a-8b

ax²+2bxy+x²-x-2xy+y
=(a+1)x²+(2b-2)xy-x+y
The first two are quadratic terms
So the coefficient is 0
a+1=0
2b-2=0
a=-1,b=1
So 5a-8b
=-5-8
=-13

Question 1: 53.5 * 35.3 + 53.5 * 43.2 + 78.5 * 46.5 question 2: 235 * 12.1 + 235 * 42.2-135 * 54.3
Question 3: 3.75 * 735-3 / 8 * 5730 + 16.2 * 62.5 who can solve the three questions

7850 5430 1620