If a two digit number, the sum of the two digits is 12, and the single digit number is 2 larger than the ten digit number, then the two digit number is 12

If a two digit number, the sum of the two digits is 12, and the single digit number is 2 larger than the ten digit number, then the two digit number is 12

fifty-seven

As shown in the figure, given ab ‖ CD, be bisection ∠ ABC, de bisection ∠ ADC, ∠ bad = 80 °, try to find: (1) the degree of ∠ EDC; (2) if ∠ bed = 70 °, try to find the degree of ∠ BCD

(1) ∫ ab ‖ CD, ∫ ADC = ∠ bad = 80 °, ∫ de bisection ∠ ADC, ∫ EDC = 12 ∠ ADC = 12 × 80 ° = 40 °; (2) let ∠ BCD = x, ∫ ab ‖ CD, ∫ ABC = ∠ BCD = x, ∫ be bisection ∠ ABC, ∫ EBC = 12x, according to the inner angle sum theorem of triangle, ∠ BEC + ∠ e = ∠ EDC + ∠ BCD

As shown in the figure, there is a point E on the BC side of the square ABCD, and the bisector of ∠ DAE intersects CD at F. the idea of rotation is used to explain AE = DF + be

As shown in the right figure, △ ADF is rotated 90 ° clockwise to obtain △ Abf ′; then there are ∠ 3 = ∠ 1, ∠ AFD = ∠ f ′, f ′ B = FD, (3 points) ∫ f ′ AE = ∠ 3 + ∠ BAE, and ∫ quadrilateral ABCD is square, ∫ ab ‖ CD, ∫ AFD = ∠ fab, (4 points) ∫ Fab = ∠ 2 + ∠ BAE, ∫ AFD = ∠ 2 + ∠ BAE, and the bisector of ∫ DAE intersects CD at F, (5 points) ∫ 1 = ∠ 2, (6 points) ∫ 3 =(7 points) ∠ f ′ AE = ∠ f ′, EA = EF ′ = DF + be. (9 points)

1,3,5,9,17,31,57,（ ）

1+3+5=9,
3+5+9=17,
5+9+17=31,
9+17+31=57,
17+31+57=105
Rule: the sum of the first three numbers equals the next number

An English multiple choice and fill in the blanks
1.would you mind my opening windows?
A.yes,i would.B.NO,you don't.C.never mind D.i'm glad to
2. Practice it () (care) fill in the blanks with the proper form of the word

The last thing you can choose is never mind,
Option a
Do you mind if I open the window?
Do I mind?
pratice it carefully

As shown in the figure, in ▱ ABCD, e is a point on CD, de: CE = 2:3, AE, be and BD are connected, and AE and BD intersect at point F, then s △ def: s △ EBF: s △ ABF=______ ．

In ▱ ABCD, ab = CD = de + CE, de: CE = 2:3, ∫ de: ab = 2:5, and ∫ CD ∥ AB, ∫ def ∫ ABF, ∫ s △ def: s △ ABF = de2: AB2 = 4:25, ∫ EBF is equal to △ ABF, ∫ s △ EBF: s △ ABF = EF: AF = 2:5 = 10:25, ∫ s △ def: s △ EBF: s △ ABF = 4

Recursive equation calculation: 1.76 + 38 × 29 + 38 × 69 2.15-1.43-4.35-4.22-

（1）76+38×29+38×69
=38×2+38×29+38×69
=38×（2+29+69）
=38×100
=3800
（2）15-1.43-4.35-4.22
=15-(1.43+4.35+4.22 )
=15-10
=5

How to square root
Who taught me to have a reward (I can't do it)

1. Every two digits from the single digit to the left is a section. If there is a decimal, every two digits from the decimal point to the right is a section. Use "," sign to separate each section;
2. Find the square root of no more than the number of the first section on the left, which is the number with the highest square root;
3. Subtract the square of the number in the highest order from the number in the first section on the left, and write the number in the second section on the right of their difference as the first remainder;
4. Multiply the number on the highest order of the quotient by 20 to try to divide the first remainder. The result is an integer as the test quotient (if the largest integer is greater than or equal to 10, use 9 or 8 as the test quotient);
If the product is less than or equal to the remainder, the trial quotient is the second digit of the square root; if the product is greater than the remainder, reduce the trial quotient and try again until the product is less than or equal to the remainder;
6. In the same way, continue to find the numbers on the other bits of the square root
Example:
2.4 4 9 4 8
/------------------
6.00'00'00'00'00
four
----
two hundred
one hundred and seventy-six
-------
two thousand and four hundred
one thousand nine hundred and thirty-six
------
forty-six thousand and four hundred
forty-four thousand and one
------
two hundred and thirty-nine thousand and nine hundred
one hundred and ninety-five thousand nine hundred and thirty-six
-------
four million three hundred and ninety-six thousand and four hundred
three million nine hundred and nineteen thousand one hundred and four
--------
four hundred and seventy-seven thousand two hundred and ninety-six

Proof: in the parallelogram ABCD, the bisector AE of the angle bad intersects DC at E. if the angle DAE = 25 degrees, how many degrees of the angle c and B?
It's in Chapter 19 quadrilateral basic knowledge standard training

It's not a proof, it's a solution
Because the angle DAE = 25 ° AE is the bisector of the angle bad
So the angle bad is 50 degrees;
Because ABCD is a parallelogram,
So angle c = angle bad = 50 degree
Angle B + angle bad = 180 °, angle B = 180 ° - 50 ° = 130 °

The mass of the earth is 5.98 × 10 to the 24th power kg, and that of Jupiter is about 1.9 × 10 to the 27th power kg
(results retain three significant digits)

The mass of Jupiter is equal to the mass of the earth
=27th power of 1.9 × 10 (24th power of 5.98 × 10)
About 3.18 × 10