The first question is to convert 9 and 16 into 3 with the square difference formula. And 4? Then substitute it into the formula, and it becomes (6x-3y)? -(4x+8y)？ Then use the square difference formula. (a+b)(a-b)=a？ -B? .

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.