x？ -2x+ 1- 1-8=0

x？ -2x+ 1-9=0

(x- 1)？ =9

x- 1= 3

solve

x 1=4 x2=-2

How to match? A solution of quadratic equation in mathematics (the other two are formula method and decomposition method)

The specific process is as follows:

1. Transform this unary quadratic equation into the form of AX 2+BX+C = 0 (this unary quadratic equation satisfies the real root).

2. Convert the quadratic coefficient into 1.

3. Move the constant term to the right of the equal sign.

4. At the same time, add half the square of the first coefficient to the left and right sides of the equal sign.

5. Write the algebraic expression on the left side of the equal sign as a complete square.

6. Simultaneously Square

7. The root of the original equation can be obtained by sorting.

Example: Solve equation 2x 2+4 = 6x.

1.2x^2-6x+4=0

2.x^2-3x+2=0

3.x^2-3x=-2

4.x 2-3x+2.25 = 0.25 (+2.25: plus 3.5 square, -2 should also add 3.5 square to make both sides of the equation equal).

5. (x-1.5) 2 = 0.25 (a 2+2b+1= 0, that is, (A+ 1) 2 = 0).

6.x- 1.5= 0.5

7.x 1=2

x2= 1