Finally we get (10x+5y) (2x-11y) = 5 (2x+y) (2x-11y).
The second question, note that x(2-x) is -(x? -2x), the formula is converted into (x? -2x)? +2(x? -2x)+ 1 is undoubtedly the square of the form 12 1, so it is (x? -2x+ 1)? . And then found (x? -2x+ 1) can be simplified as (x- 1)? .
Finally we get (x- 1) 4.
The third question, first extract x n * y and convert the formula into x n * y (x? -Really? ) then use the square difference formula.
Finally, x n * y (x+y) (x-y) is obtained.
The above * stands for multiplication and * stands for power. For example, 2 5 is 2 to the fifth power.