Ask "mathematics class practice and evaluation" seventh grade (1) self-evaluation (5.5

Ask "mathematics class practice and evaluation" seventh grade (1) self-evaluation (5.5

I want the answer to that, too
Alas
I'd better make it myself

Simple calculation of 8 / 13 times 4 / 5 plus 4 / 5 times 5 / 13

Eight out of thirteen times four out of five plus four out of five times five out of thirteen
=4/5x(8/13+5/13)
=4/5x1
=4/5

Who can tell me which adjective is the most appropriate to describe the appearance of indifference and inner fanaticism?
It seems to be a four word idiom that I can't remember at the moment
I want to find a poetic word to describe people.

It's a bit difficult. It's like the undercurrent is surging, but it doesn't look right

Complex fraction calculation
Mathematics 2-13 question 12

One half

(32 + x) = 4 (x + 5) to solve the equation!

(32+x)=4(x+5)
32+x=4x+20
4x-x=32-20
3x=12
x=4

Simple calculation: 125% * 88

0.125X（80+8）
=0.125X8X10+0.125X8
=10+1
=11

As shown in the picture, a student wants to measure the height of the flagpole. At a certain time, he measured the shadow length of a 1-meter-long bamboo pole when it was placed vertically. When measuring the shadow length of the flagpole at the same time, because the flagpole was close to a building, the shadow did not fall on the ground completely, but some of it fell on the wall. He measured the shadow length of the bamboo pole on the ground as 21 meters, and the shadow height left on the wall as 2 meters

Let C be CE ⊥ AB over e, ∵ CD ⊥ BD, ab ⊥ BD, ∵ EBD = ∠ CDB = ∠ CEB = 90 °, the quad cdbe is rectangular, BD = CE = 21, CD = be = 2, let AE = XM. Then 1:1.5 = x: 21, the solution is: x = 14, so the flagpole height AB = AE + be = 14 + 2 = 16m

A0a × AA is equal to

A0A×AA=A^2*1000+A^2*10+A^2*100+A^2=1000A^2+100A^2+10A^2+A^2

The odd function y = (FX) with the domain (- 1,1) is a decreasing function, and f (A-3) + F (9-A ^ 2)

According to the domain of definition, A-3 ∈ (- 1,1) leads to a ∈ (2,4); 9-A ^ 2 ∈ (- 1,1) leads to a ∈ (- 10, - 8) U (√ 8, √ 10); because f (x) is an odd function, f (A-3) ＜ - f (9-A ^ 2) = f (a ^ 2-9), and f (x) is a decreasing function, so A-3 ＞ a ^ 2-9, that is a ^ 2-a-6 = (A-3) (a + 2) ＜ 0, that is - 2 ＜ a

Science high school mathematics elective which several
I'm from Zhuzhou, Hunan Province. Which one should I learn

Choosing science should start from the second year of high school. Generally, five books are studied in the first year of high school, namely compulsory 1, compulsory 2, compulsory 3, compulsory 4, compulsory 5. When choosing Science in the second year of high school, we have to learn elective 2-1, 2-2, 2-3. Finally, we have to learn two books in the third year of high school. These two books are different in different provinces. I know that in Jiangsu, we study elective 4-2 and elective 4-4, which are matrix and parametric equation respectively, just like elective 4-1 and elective 4-3 It's geometry and inequality