The ratio of story books to literature books is 4:5, and story books are () percent less than literature books

The ratio of story books to literature books is 4:5, and story books are () percent less than literature books

If we regard the number of literature books as unit "1", the number of story books is equivalent to 4 / 5
How many percent less story books than literature books: (1-4 / 5) △ 1 = 0.2 = 20%
The ratio of story books to literature books is 4:5, and story books are 20% less than literature books

It is known that the three vertices of triangle ABC are a (0.0) B (1.1) C (4.2) (1) the equation for finding the circumcircle of triangle
(2) Find the chord length of the line where the height of AB is cut by the circumscribed circle

The equation of the triangle circle is (x-a) &\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\r & # 178; - 2 (4-A) & # 178; + (2-B) & # 178; = R

What's the difference between take charge of and take the charge of?
Please list some sentences and translate them into Chinese for my understanding,

The boss asked him to take charge of the office for a few days while she was away

A fraction is 13 / 27, the numerator plus a certain number, and the denominator minus the same number to become 7 / 3?

Let a number be X
(13+x）/(27-x)=7/3
39+3x=189-7x
10x=150
x=15
That is, a certain number is 15

Some can modify countable nouns, whether it can modify uncountable nouns, and why

Yes
That's what some says. Just remember

Simplify [vector AB vector CD] - [vector AC vector BD]

[vector AB vector CD] - [vector AC vector BD]
=Vector AB + vector BD vector CD vector AC
=Vector Ad vector ad
=Vector 0

The word forever only belongs to us

The word only belong to us forever

In the isosceles RT △ ABC, P is the midpoint of the hypotenuse BC, D is any point on BC, de ⊥ AB, DF ⊥ AC, prove: PE = PF, PE ⊥ PF
Please, please!

Connect AP
AE=DF=CF AP=CP PAE=PCF=45
Triangle ape is equal to CPF
PE=PF
APE=CPF
EPF=APE+APF=CPF+APF=APC=90
PE⊥PF

What's the plural form of French? Do you need to add the definite article the in front of it when you express someone from a certain country

Or French
No need to add

In the acute triangle ABC, ab = 1 + √ 3, BC = 2, AC = √ 2, find the area of triangle ABC
hurry up

It's very simple
It is known that in the acute triangle ABC, ab = 1 + √ 3, BC = 2, AC = √ 2
Then AC square = AB square + BC square - 2Ab * BC * CoSb
CoSb = √ 3 / 2 and SINB = 1 / 2
So the area of triangle ABC = (1 / 2) * AB * BC * SINB = (1 + √ 3) / 2