7- equals 10, which involves the basic knowledge and algorithm of addition and subtraction of positive and negative numbers in mathematics. In order to understand the solution of this problem more intuitively and easily, the mathematical algebraic equation method can be used.

Let 7- how much is equal to 10 and x, then 7-x = 10. According to the law of mathematical operation, X = 7- 10, and the result is X = 1-3, that is, 7-( 1-3) equals 10.

How to divide a circle into seven equal parts;

Divide the diameter of the circle into 7 equal parts, take 1 to 7, take 7 points 2 as the center and the length of 1 to 7 as the radius, make the arc intersect with the extension line of the horizontal diameter at two points AB, connect two points A and B to each even point 2.4.6 respectively, and extend the intersecting circle to seven points abcdefg, that is, seven points.