The solution equation: x2 − 7 = 5 + X

The solution equation: x2 − 7 = 5 + X

It is obtained by moving the term, x2-x = 5 + 7, merging the similar terms, - x2 = 12, and changing the coefficient to 1, x = - 24

By using the properties of the equation, the following equations are solved: (1) 3x = 2x + 12; (2) x / 2-3 = 5

Use the basic properties of the equation to solve the following equation 3x = 2x + 7

3x=2x+7
3x-2x=2x+7-2x
x=7

What do 6 * 4 and 56 * 40 in pure cotton 6 * 4 56 * 40 mean respectively? What is yarn count?

Yarn count and density, yarn count Baidu search, that is the yarn thickness

The average number of a, B and C is 80, and the ratio of these three numbers is 1; 2; 3. They are? The best answer in five minutes

The average number of a, B and C is 80. The ratio of these three numbers is 1; 2; 3. They are 40, 80 and 120 respectively
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The decomposition of 1-a2-b2 + 2Ab results in______ ．

1-a2-b2 + 2Ab = 1 - (A2 + b2-2ab), = 1 - (a-b) 2, = (1 + a-b) (1-A + b). So the answer is: (1 + a-b) (1-A + b)

One third of a is equal to one fourth of B. If a is 120, then B is 120

160

(a + 1) and (3-2a)

That is, 1 / (a + 1) & 178; > 1 / (3-2a) & 178;
So (a + 1) &
a4
The denominator is not equal to 0
A4 and a ≠ - 1

1 / 9 of the number a is equal to the number B (the number a is not equal to 0), and the number a is 9 times the number B. (judgment)

That's right
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Let a be a 3 × 4 matrix with rank 3. If η 1 and η 2 are two different solutions of a system of non-homogeneous linear equations AX = B, then its general solution is

η = a η 1 + B η 2, a, B are constants!
η is the general solution!