The solution by substitution: {3x-5y = 9,2x + 3Y = - 6

RELATED INFORMATIONS

• 1. If 1 / x minus 1 / y = 3, find (5x + 2xy-5y) / (x-4xy-y)
• 2. If ab ≠ 0, then the value of | a | a + | B | B cannot be () A. 0B. 1C. 2D. -2
• 3. If ab ≠ 0, then the value of | a | a + | B | B cannot be () A. 0B. 1C. 2D. -2
• 4. In the equilateral triangle ABC, D is the middle point on the edge of BC, and ad is the edge of the equilateral triangle ade In the equilateral triangle ABC, D is the midpoint on the edge of BC, and ad is the edge of the equilateral triangle ade. (1) find the degree of angle CAE; (2) take the midpoint f on the edge of AB, connect CF, CE,
• 5. In the original operation of real number, we define the new operation "⊕" as follows: when a ≥ B, a ⊕ B = a; when a < B, a ⊕ B = B & # 178 Let f (x) = (1 ⊕ x) - (2 ⊕ x) x, X ∈ [- 2,2] 1, find the analytic expression 2 of F (x), and find the range of F (x)
• 6. The difference between imaginary number and real number
• 7. Natural number, integer, real number and so on There are natural numbers, integers, positive numbers, negative numbers, rational numbers, irrational numbers, and so on
• 8. The difference between integer, real number, natural number and rational number? What are integers and include 0? What is a real number and does it include circular decimals? What are rational numbers and irrational numbers? What is natural number and whether it includes 0
• 9. For any positive real numbers a and B, the size relation between (a ^ 2 + B ^ 2) / 2 and ab is studied For any positive real number a, B, the size relation with AB is studied (1) Substituting the numerical value, comparing the size, finding the law ① When a = 3, B = 1, (a ^ 2 + B ^ 2) / 2 > AB; ② When a = root 3, B = root 3, (a ^ 2 + B ^ 2) / 2___ ab; ③ a=___ ,b=___ (a ^ 2 + B ^ 2) / 2___ ab; Conjecture: for any positive real number a, B, (a ^ 2 + B ^ 2) / 2___ ab. (2) Construct graph to verify conjecture The algebraic formula (a ^ 2 + B ^ 2) / 2 can be expressed by the sum of the areas of two isosceles right triangles whose waist length is a and B respectively. The above conjecture can be verified by means of the splicing and segmentation of the two triangles (3) Application Explore: the maximum area of a right triangle with a hypotenuse of 5
• 10. If a and B are real numbers, compare a ^ 2 + B ^ 2 with ab
• 11. Substitution of {3x-5y = 0,2x-3y = 1 into elimination method
• 12. How to solve 2x-y = 7 2x + 3Y = 1 3x + 5y21 5y-3y = 1 by algebraic elimination method?
• 13. The substitution elimination method is used to solve the equations 2x + 5Y = - 5,3x-y = 18
• 14. If a, B and C are non-zero rational numbers, what is the value of AB / | ab | + BC / | BC | + AC / | AC |
• 15. Evaluation: (1) if a and B are non-zero rational numbers, and a | a | + B | B | = 0, find the value of ab | ab |; (2) it is known that a is the smallest positive integer, B and C are rational numbers, and | 2 + B | + (3a + 2C) 2 = 0. Find the value of formula 4ac + c-a2 + C2 + 4
• 16. In the triangle ABC, AB * BC = 3, the area s of triangle ABC ∈ [root 3,3 / 2], then the value range of the angle between AB and BC
• 17. In the triangle ABC, if the angle a ∈ [π / 4, π / 3], and its area is s, then the value range of the vector ab · vector AC
• 18. In the acute triangle ABC, ∠ C = 2 ∠ B, then the value range of ∠ B is ()
• 19. In the acute angle △ ABC, if ∠ C = 2 ∠ B, the value range of CB is______ ．
• 20. If the three sides of the triangle ABC are a, B, C and satisfy the following conditions: A2 + B2 + C2 + 338 = 10A + 24B + 26c, then the height of the longest side of the triangle ABC is () A. 8B. 125C. 6013D. 245