Make the sum of the three numbers of the horizontal, vertical, oblique and diagonal angles of the nine squares in the square matrix equal to 0 ___ -3 ____ ___ 0 ___ ___ ____ -1

Make the sum of the three numbers of the horizontal, vertical, oblique and diagonal angles of the nine squares in the square matrix equal to 0 ___ -3 ____ ___ 0 ___ ___ ____ -1

1 -3 2
1 0 -1
-2 3 -1

Solving the equations {2s-3t = 11,3s + 4T = - 9} by the method of addition, subtraction and elimination

4（2s-3t）=44① 3（3s+4t）=-27② ①+②=17s=17 s=1 t=-3

If the polynomial f (x) is divided by X-1 and 3, and divided by X-2 and 2, then f (x) is divided by (x-1) (X-2)

The remainder of polynomial f (x) divided by X-1, X-2 and x-3 are 1, 2 and 3 respectively
f(1)=1,f(2)=2,f(3)=3
This shows that 1,2,3 are the three roots of the equation f (x) - x = 0
So f (x) - x must have the factor (x-1) (X-2) (x-3)
So what we're looking for is X

If the algebraic formula 2x ^ 2 + 3x + 7 = 8, then the value of the algebraic formula 4x ^ 2 + 6x-1 is?
A 2
B 3
C16
D17 hehe, the topic is wrong. Forget it

Integral approach
2x^2+3x+7=8
2x^2+3x=1
so
4x^2+6x=2
Substitute 4x ^ 2 + 6x-1
The original formula is 1

25 * (- 0.4) * 2013 * (- 0.1) calculation (- 6 branches 1 + 3 / 20 + 5 branches 4-11 / 12) * - 60) calculation
-17 * 9 of 99 and 18
-34 * 2 of 7 + 1 of 3 * (- 13) - 5 of 7 * 0.34

25*(-0.4)*2013*(-0.1)
=-10*（-0.1）*2013
=2013
(- 6 branches 1 + 3 / 20 + 5 branches 4-11 / 12) * (- 60)
=1/6*60-3/20*60-4/5*60+11/12*60
=10-9-48+55
=8
-17 * 9 of 99 and 18
=（-100+1/18）*9
=-100*9+1/18*9
=-900+0.5
=-899.5
-2 of 13 * 3-0.34 * 2 of 7 + 1 of 3 * (- 13) - 5 of 7 * 0.34
=-13*（2/3+1/3）-0.34*（2/7+5/7）
=-13-0.34
=-13.34

The area of a triangle is 54 square meters, the bottom is 9 meters, and how high is the triangle?

54 × 2 △ 9 = 12 (m)

Number a divided by number B, the quotient is 47, the difference between the two numbers is 21? (solved by equation)

Let B be x and a be 47x. X-47x = 21 & nbsp; 37x = 2137x × 73 = 21 × 73 & nbsp; & nbsp; & nbsp; X = 49; a be 47x = 47 × 49 = 28; a and B be 28 and 49 respectively

The perimeter of the bottom surface of a cube is 12 decimeters. How many square decimeters does the tank cover?

(12 / 4) × (12 / 4) = 9 (square decimeter)

Simple calculation for 0.39 * 0.25 * 026

0.39*0.25*0.26=39*25*26/1000000
=(40-1)*25*26/1000000
=(40*25*26-25*26)/1000000
=(1000*26-50*13)/1000000
=(26000-650)/1000000
=25350/1000000
=0.02535

In RT △ ABC, the bisector of acute angle a intersects with the bisector of the adjacent complementary angle of acute angle B at point D, then ∠ ADB=______ Degree

If the size of acute angle ∠ A is x, then the adjacent complementary angle of acute angle ∠ ABC is 90 ° + X; then ∠ ADB = 180 ° - (x2 + 90 ° - x + 45 ° + x2) = 45 °