1.c (integral equation) If there is only one unknown in the equation and both sides are algebraic expressions about the unknown, it is called a unitary integral equation. The one-dimensional linear equation and quadratic equation are all integral equations. When m=- 1, the equation becomes a linear equation.

2 . k≦- 1

3.

5x？ -Root sign 5x-6=0

X=[ (root number 5)+- under the root number (5-4×5×(-6))]/ 10, where x is a power sign, and the formula method is to find the root.

X=[ (radical number 5)+-5 radical number 5)]/ 10

X=(3 5)/5 or -(2 5)/5.

4. The length of one side against the wall is X, and the length of the other side is Y. (It is difficult to set the length and width without drawing.)

xy= 130

x+2y- 1=32

Calculation: x= 13, y= 10 or x=20, y=6.5.

5. Solution: m= 1+- radical number 2, n= 1+- radical number 2.

Because m and n are two unequal real numbers,

So m= 1+ radical number 2, n= 1- radical number 2.

Or m= 1- radical number 2, n= 1+ radical number 2.

Is it algebra 2m? +4n？ -4+ 1999=__20 13-4 radical number 2 or _20 13+4 radical number 2 _ _ _ _ _ _.