A new algorithm is provided: a ∧ B = A & # 178; + 2Ab if 2 ∧ (- x) = - 2 + X, calculate the value of X

A new algorithm is provided: a ∧ B = A & # 178; + 2Ab if 2 ∧ (- x) = - 2 + X, calculate the value of X

2※（-x）=4-4x=-2+x
5x=6
x=6/5

*A * b = A & sup2; + 2Ab. For example, 3 * (- 2) = 3 & sup2; + 2 × 3 × (- 2) = - 3, try to find 2 * x = 2 of 2 * (- 1)
And (- 2) * x = - 2 + X, find the value of X

2*（-1）=2^2+2×2×(-1)=0
2*x=2
4+4X=2
X=-1\2
（-2）*x=-2+x
4-4X=-2+x
x=6\5

The area of a triangle is 2 / 7 square meters, the bottom is 8 / 5 meters long, how many meters is the height? Hurry up!

Height = 2 / 7 × 2 △ 5 / 8 = 32 / 35m
Do not understand can ask, help please adopt, thank you!

The solution of the equation KX = 4 of X is a positive integer, and the integer value of K can be obtained

K * x = 4 write the equation of X first
x=4/k
Because the solution of X is a positive integer, 4 / K is also a positive integer
So k = 1,2,4
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The circumference of a semicircle is 20.56 cm. What is the area of the semicircle?
Although I didn't give him points first, I gave him 50 points for a good answer!
This topic is very difficult for everyone to pay attention to!

Let the diameter be X
3.14×x÷2+x=20.56
1.57x+x=20.56
x=20.56÷2.57
x=8
The square of 3.14 × (8 △ 2) is 2
=50.24÷2
=25.12 square centimeter

How to calculate 73.6-13.6 × 21.5 △ 4

73.6－13.6×21.5÷4
=73.6－13.6÷4×21.5
=73.6－3.4×21.5
=73.6-73.1
=0.5

As shown in the figure, in △ ABC, ∠ a = 50 °, BP bisects ∠ ABC, CP bisects ∠ ACB, then the degree of ∠ BPC is___ ．

∵ in △ ABC, ∵ a = 50 °, ∵ ABC + ∵ ACB = 180 ° - 50 ° = 130 °. ∵ BP bisection ∵ ABC, CP bisection ∵ ACB, ∵ PBC + ∵ PCB = 12 (∵ ABC + ∵ ACB) = 12 × 130 ° = 65 °, ∵ BPC = 180 ° - 65 ° = 115 °

Let the sum of plane vectors A1, A2, A3 be a1 + A2 + a3 = 0. If plane vector b1b2b3 satisfies | B ι = 2 | a ι, and a ι rotates 30 degrees clockwise in the same direction as B ι, where ι = 1,2,3, how can we get B1 + B2 + B3 = 0?

A1 + A2 + a3 = 0 vector
Ψ 2A1 + 2A2 + 2A3 = 0 vector
Then the directed line segments represented by vectors 2A1, 2A2 and 2A3 can be connected end to end
Rotate the vectors 2A1, 2A2 and 2A3 30 ° counterclockwise,
The directed line segment can also be connected end to end
The directed line segments represented by vectors B1, B2 and B3 can be connected end to end
The vector B1 + B2 + B3 = 0

It is known that the top, bottom and height of a trapezoid are 9.2 cm, 6.5 cm and 0.4 cm respectively. How to find the area of the trapezoid

The area is: (2 / 9 + 5 / 6) × 0.4 △ 2
=19 / 18 × 1 / 5
=19 / 90 square centimeter

Let a, B ∈ R, and a ≠ 2. The function f (x) = LG1 + ax1 + 2x defined in the interval (- B, b) is odd. (1) find the value range of B; (2) discuss the monotonicity of function f (x)

The solution (1) f (x) = LG1 + ax1 + 2x (- B & lt; X & lt; b) is an odd function, which is equivalent to: for any x ∈ (- B, b), there is f (- x) = - f (x) & nbsp; ① 1 + ax1 + 2x & gt; 0 & nbsp; ② the formula is lg1-ax1-2x = - LG1 + ax1 + 2x = LG1 + 2x1 + ax, from which we can get 1-ax1-2x = 1 + 2x1 + ax, that is a2x2 =