How are 1,3,7,8,2,4,6,5,9 classified and what are the rules

How are 1,3,7,8,2,4,6,5,9 classified and what are the rules

According to the Chinese phonetic alphabet one tone level (1,3,7,8), three tone turn (5,9), four tone drop (2,4,6) to divide

1. Eight minus three equals five. 2. Five plus three equals eight
1. Eight minus three is five
2. Five plus three is eight
3. Five times three is fifteen
4. Fifteen divided by three is five

1. Eight minus three is five
Eight minus three equals five.
2. Five plus three is eight
Five plus three equals eight.
3. Five times three is fifteen
Five multiplied by three is fifteen.
Five times three is fifteen.
4. Fifteen divided by three is five
Fifteen divided by three equals five.

If the sum of coefficients of the expansion of binomial (2x-a / x) ^ 5 is 1, then the coefficient of the second term in the expansion is?

When x = 1, the sum of coefficients is to bring x = 1 into the formula; then we can see that a = 1; the second term is (C below 5 above 1) (2 ^ 4) (- 1) = - 80

If A-B = 5, ab = 24, find the value of a + B, a + B

（a +b）²=（a -b）²+4ab
=25+96
=121
A + B = 11 or - 11

Solve the equation with the collocation method: the square of x plus x minus 1 equals 0

x^2+x-1=0
x^2+x=1
(x^2+x+1/4-1/4)=1
(x+1/2)^2=5/4
x+1/2=±(√5)/2
x1=(1+√5)/2
x2=(1-√5)/2

3.6x-4 * 3.5 = 2 how to solve the equation? Speed

3.6x-14=2
3.6x=16
X = 40 / 9

Let n-dimensional vector A1, A2 be linearly independent, A3, A4 be linearly independent. If A1, A2 are orthogonal to A3, A4 respectively, it is proved that A1, A2, A3, A4 are linearly independent

It is known that n-dimensional vector group A: A1, A2 are linearly independent, B1, B2 are linearly independent, and A1, A2 are orthogonal to B1, B2 respectively. It is proved that A1, A2, B1, B2 are linearly independent
Let x 1A1 + X 2A2 + y 1B1 + y 2B2 = 0, and prove that x 1 = x 2 = Y 1 = y 2 = 0
x1a1+x2a2=-y1b1-y2b2
Because A1 and A2 are orthogonal to B1 and B2 respectively,
So X1A1 + x2a2 and B1, B2 are orthogonal,
Thus, X1A1 + x2a2 and - y1b1-y2b2 are also orthogonal,
So X1A1 + x2a2 = - y1b1-y2b2 = 0 (premise: real vector)
Because A1 and A2 are linearly independent, X1 = x2 = 0 is obtained from X1A1 + x2a2 = 0
Because B1 and B2 are linearly independent, Y1 = y2 = 0 is obtained from - y1b1-y2b2 = 0
So A1, A2, B1, B2 are linearly independent

How many processes does the power of X - 14x + 49 equal

x²-14x+49
=x²-2×x×7+7²
=(x-7)²

Given that a ≤ 1, the set [a, 2-A] has and only has three integers, then the value range of a is______ ．

When a = 1, 2-A = 1, not suitable; when a = 0, 2-A = 2, not suitable; when a = - 1, 2-A = 3, not suitable

It is known that X & # 178; - 2 (M + 1) x + M & # 178; + 5 is a complete square
(1) Finding the value of M
(2) Solve the equation x & # 178; - 2 (M + 1) x + M & # 178; + 5 = 0

(1) (M + 1) ^ 2 = m ^ 2 + 5, so m = 2
（2）x=3