In the original algorithm of rational number, we define a new operation "(+)" as follows: When a > or = B, a (+) B = B × B

In the original algorithm of rational number, we define a new operation "(+)" as follows: When a > or = B, a (+) B = B × B

1（+）x=1
3(+)x=x²=4
Original formula = 1 × 2-4 = - 2

In the original algorithm of rational number, we define a new operation "(+)" as follows: when a is greater than or equal to B, a (+) B = BXB;
When a is less than B, a (+) B = a, then the value of (1 (+) 2) X3 - (3 (+) 2) is? (x and - are still multiplication and subtraction signs in rational number operation)

(1（+）2)x3-(3（+）2) = (1x3)-4 = -1

Solve the equation x + 4 parts of 1 x = 60

x+x/4=60
4x+x=60*4=240
5x=240
x=240÷5
x=48

If A1, A2, A3, A4 and A5 are four-dimensional vectors, they must be linear_____

Theorem: any n + 1 n-dimensional vector must be linearly related
So the answer to your question is linear
Based on the above inference

We know that the value of the square of the formula 3x + 5-7x is - 2, and find the value of the square of 14x - 6x + 5

The square of ∵ 3x + 5-7x is - 2
The square of 3x + 5-7x = - 2
-7x²+3x+5=-2
7x²-3x=7
The square of 14x - 6x + 5
=2(7x²-3x)+5
=14+5
=19

In the population n (60,15 & sup2;), a sample with a capacity of 81 is randomly selected. What is the probability that the absolute value of the difference between the sample mean and the population mean is greater than 4

It's simple. I need time to do it for you

The univariate quadratic equation of X is x2 + MX + M = 0, and the left side is the complete square
What is m equal to? What is the root of the equation?

The univariate quadratic equation of X is x2 + MX + M = 0, and the left side is the complete square
x^2+mx+m=0
[x+m/2]^2-m^2/4+m=0
Because the left side is completely square, so: - m ^ 2 / 4 + M = 0
m^2-4m=0
M = 0 or M = 4
1.m=0
x^2=0
x=0
2.m=4,
x^2+4m+4=0
[x+2]^2=0
x=-2

As shown in the figure, in trapezoidal ABCD, ad ∥ BC, diagonal AC and BD intersect vertically at O, Mn is the median line of trapezoidal ABCD, ∠ DBC = 30 °, verification: AC = Mn

It is proved that: ∵ ad ∥ BC, ∵ ADO = ∠ DBC = 30 °, in RT △ AOD and RT △ BOC, OA = 12ad, OC = 12bc, ∵ AC = OA + OC = 12 (AD + BC), ∵ Mn = 12 (AD + BC), ∵ AC = Mn

What is the cubic power of 0.007

0.000000343

If s = 1 + 11 + 111 + 1111 + 11111 +. + 1.1 (30 1s), what is the ten digit number of S?

Because there are 29 numbers with 10 bits, and each time they are 1, 29 ones are added together, and the 3 in each bit is added, the result is 9 + 3 = 12