How to calculate x squared - 2x = 3 and X squared - 2x = x?

How to calculate x squared - 2x = 3 and X squared - 2x = x?

x²-2x=3
X²-2X-3=0
(X-3)(X+1)=0
X-3 = 0 or x + 1 = 0
X1=3,X2=-1
x²-2x=x
X²-2X-X=0
X²-3X=0
X(X-3)=0
X = 0 or x-3 = 0
∴X1=0,X2=3

How to calculate the square of X - 2x - 2 = 0

Solution
x²-2x-2=0
x²-2x=2
x²-2x+1=3
(x-1)²=3
Ψ X-1 = √ 3 or X-1 = - √ 3
‖ x = 1 + √ 3 or x = 1 - √ 3

Prove by induction: think (1) x > = - 1, n > = 1, (1 + n) ^ n > = 1 + NX (2) 2 ^ n > = n ^ 2 (n > = 5)

1, (1 + n) ^ n should be, (1 + x) ^ n
When n = 1, the equal sign holds
Suppose n = k, the equal sign holds, that is, (1 + x) ^ k > = 1 + KX
When n = K + 1,
(1+x)^（k+1）=,(1+x)^k*（1+x）>=（1+kx）（1+x）=1+kx+x+kx^2》1+（k+1）x
establish
2. When n = 5, it holds. Suppose n = k holds 2 ^ k > = k ^ 2
When n = K + 1, 2 ^ k + 1 = 2 * 2 ^ k > = 2K ^ 2 = k ^ 2 + 2K + 1 + K ^ 2-2k-1 consider the function K ^ 2-2k-1, because it is an increasing function from 5 to positive infinity, so its minimum value is 14, which is greater than 0
k^2+2k+1+k^2-2k-1》k^2+2k+1=（k+1）^2
That is, n = K + 1 is also true

How to judge east longitude, west longitude, south latitude and north latitude on the map

Up north down south, left West, right east, horizontal is the precision, vertical is the latitude

If the sum of three consecutive even numbers is 18 and the largest even number is x, then the equation is

x-4+x-2+x=18
3x=24
∴x=8
x-2=8-2=6
x-4=8-4=4

4 + ㏒ logarithm of 3 with 2 as the base

=The fourth power of 2 × the ㏒ logarithm power of 3 with 2 as the base
=16×3
=48

How to calculate 25 times 60?

25*60
=25*4*15
=100*15
=1500

If AB = 2, a + B = 3, then A2 + B2=______ ．

∵ab=2，a+b=3，∴a2+b2=（a+b）2-2ab=32-4=5．

The function f (x) = AX2 + 6x-1 increases monotonically in the interval [- 1,2], and the value range of real number a is obtained

When a = 0, f (x) = 6x-1 is a monotone increasing function
When a > 0, according to the meaning of the topic, the axis of symmetry of the function should be less than or equal to - 1, that is, 6-2a should be less than or equal to - 1

5 ha 400 M2 = [] ha

1 ha = 10000 M2
400 M2 = 0.04 ha
5 ha 400 M2 = [5.04] ha