First simplify and then evaluate: - (x2 + Y2) + [- 3xy - (x2-y2)], where x = - 1, y = 2
The original formula = - x2-y2-3xy-x2 + y2 = - 2x2-3xy, when x = - 1, y = 2, the original formula = - 2 × (- 1) 2-3 × (- 1) × 2 = 4
RELATED INFORMATIONS
- 1. First simplify, then evaluate: - (square of X + square of Y) + [- 3xy - (square of X - square of Y)], where x = - 1, y = 2
- 2. 2,4 of 5,9 of 10,16 of 17, find the law
- 3. When the real number m takes what value, the equation 4x + (m-2) x + (m-5) = 0 has: (1) the absolute value of positive root is greater than that of negative root When m is a real number, the equations 4x + (m-2) x + (m-5) = 0 are as follows: (1) Is the absolute value of positive root greater than that of negative root? (2) Both are greater than 1?
- 4. If the absolute value of equation - X & # 178; + 4x-3 = KX has three real solutions, then K=
- 5. If there are exactly three different real solutions to the equation of X: the second power of X - 2 times the absolute value of X + 2 = m, please guess the value of M and verify it
- 6. To solve the equation with absolute value: given that x is a real number, M = | x + 1 | + | x + 2 | + | x + 3 |, find the minimum value of M
- 7. If the absolute value of the equation x + 1 plus the absolute value of X-1 about x equals that a has a real root, then the value range of the real number a is () A a is greater than or equal to 0 B A is greater than or equal to 0 C A is greater than or equal to 1 D A is greater than or equal to 2
- 8. If a is the real root of the equation x + log3x-3 = 0 and B is the real root of X + 3 ^ x-3, find a + B
- 9. The equation log3x ^ 2 + mlog1 / 3x ^ 2 + 5 = 0 of X has two equal real roots on (9, ∞), then the range of real number m is
- 10. The interval of a real root of equation x ^ 3-x-1 = 0 is
- 11. Simplification: - (square of X - square of Y) + [- 3xy - (square of X + square of Y)]: Xy - {the square of 1 / 2x - [the square of 3y-2 (the square of xy-3y) - 1]} If we know the square of a = 2A - 3AB, B = the square of a + 2Ab, we can find:
- 12. Calculate (3xy2-6x2y) / (- 2x) =___ .
- 13. Calculate (3xy2-6x2y) / (- 2x) =___ .
- 14. Simplification: (2x2y-3xy2) - (6x2y-3xy2)
- 15. What is (2x square y + 3xy Square) - (6x square y-3xy Square) equal to
- 16. Find (the square of 2x - 3xy + the square of 4Y + the square of 4Y) x (- 2XY)
- 17. The coefficient of the quadratic power of X and YZ
- 18. -The degree of 2 / 3x square YZ is () and the coefficient is () The square of xy-y + the square of 2x is ()
- 19. What is the coefficient of the cube of the square B of minus 3 / a? What is the degree?
- 20. The coefficient of "3 / 2 of negative axis" I'll die if I don't preview The coefficient of minus one third of the square of axis Can it be written as - 1 / 3 Can you write down the problem that coefficient should pay attention to -How did one third come from