1. From the equation 3x-2y+6=0, we can get the formula that X represents Y: When x=2, Y =;;
2. When k=, it is the solution of equation x+ky+ 1=0;
3. Write binary linear equations with solutions;
4. If the binary linear equations are known as x-y =, x+y =;
5. The store shipped 120 washing machines, each at the price of 440 yuan. You can get a profit of 15% of the selling price for every one sold, and two of them are damaged and sold at a 20% discount on the original price. After these washing machines are sold, the net profit is RMB;
6. It is known that no matter what the value of x is, there is (a+2b) x+(a-2b) = 5x+3, then a = b =
7. If the lengths of the three sides of a triangle are 7, 10 and x respectively, the value range of x is;
8. In Δ Δ ABC, it is known that ∠A= ∠B= ∠C, then the shape of the triangle is triangle;
9. It is known that the sum of the inner angles of a polygon is twice the sum of the outer angles, and this polygon is a polygon;
10. The acute angle formed by bisectors of two acute angles of a right triangle;
1 1. The sun in the inner corner of the polygon is equal to 5040 degrees. What is it?
Where is the diagonal line? .
12. If the circumference of an isosceles triangle is 2 1 and the difference between two sides is 3, then the length of each side is respectively;
Second, multiple-choice questions: (3 points 8=24 points)
13. in the equation y=mx+n, when x=2, y =1; When x=3, y=3. Then the values of m and n are ()
A.B. C. D。
14. This equation is a binary linear equation and must satisfy ().
A.≠0 B. ≠-3 C. ≠3 D. ≠2
15. If the inner angle of a regular polygon is 144, then the polygon is ().
A. Regular decagon, regular nonagon, regular octagon and regular heptagon
16. The following judgment is correct ()
A. One outer angle of a triangle is equal to the sum of two inner angles. The outer angle of a triangle is greater than any inner angle.
At least one angle in the C triangle is greater than or equal to 60 d. The outer angle of the triangle is the adjacent complementary angle of the inner angle.
17. The sum of the internal angles of (n+1) polygons is greater than the sum of the internal angles of n polygons ().
360 c n 180d n 360
18. The regular polygon that can cover the ground is ().
A. regular pentagon, regular hexagon, regular heptagon and regular octagon
23.(X and y are unknown)
4.24. (5 points in this question) It is known that the sum of the values of X and Y in the equation of X and Y is equal to
2, find the value of m.