Solve equations 1. (x / 2 + Y / 5 = 13 (x-1) = 11 + 2 (y + 4)) 2. (5x + 4Y + Z = 0 3x + y-4z = 11 x + y + Z = - 2) pay attention to see clearly Detailed to the process, direct to the answer does not give points

Solve equations 1. (x / 2 + Y / 5 = 13 (x-1) = 11 + 2 (y + 4)) 2. (5x + 4Y + Z = 0 3x + y-4z = 11 x + y + Z = - 2) pay attention to see clearly Detailed to the process, direct to the answer does not give points

1. (1) x / 2 + Y / 5 = 1 (General Division) get (3) (2) 3 (x-1) = 11 + 2 (y + 4) (sort out (4) (3) 5x + 2Y = 10 (4) 3x-2y = 22 (add with (3)) 8x = 32x = 4 to (3) 2Y = 10-5x = 10-20 = - 10Y = - 52, (1) 5x + 4Y + Z = 0 (subtract with (3)) get (4) (2) 3x + y-4z = 11

When solving the equations {5x-4y = - 6,5x + 4Y = - 14 by using the method of addition, subtraction and elimination, if we find the value of X first, we should put two equations (); if we find the value of Y first, we should put two equations ()
The solution of the equation is

If we find the value of X first, we should add the two equations; if we find the value of Y first, we should subtract the two equations,
The solution of the equation is ({x = - 2, y = - 1)

The zero point of the function f (x) = - x2 + 5x-6 is ()
A. （-2，3）B. 2，3C. （2，3）D. -2，-3

From - x2 + 5x-6 = 0, we can get x = 2 or x = 3. Therefore, the zero point of the function is 2 or 3

If f (x) = (AX-1) / (x + 1) is a decreasing function on (negative infinity to - 1), then the value range of a is?
Write down the process, thank you

f(x)=[a(x+1)-(a+1)]/(x+1)
=a(x+1)/(x+1)-(a+1)/(x+1)
=a-(a+1)/(x+1)
Is a decreasing function on (negative infinity to - 1)
So - (a + 1) / (x + 1) is a decreasing function on (negative infinity to - 1)
So (a + 1) / (x + 1) is an increasing function on (negative infinity to - 1)
If the inverse proportion function is an increasing function, then a + 1

The monotone increasing interval of function f (x) = log12 (2x2-5x + 3) is______ ．

Let g (x) = 2x2-5x + 3, then G (x) is a decreasing function when x < 1, and G (x) is an increasing function when x > 32. And y = log12u is a decreasing function, so f (x) = log12 (2x2 − 5x + 3) is an increasing function when (- ∞, 1). So the answer is: (- ∞, 1)

Find the range of the following function values Y 1, y = root x ^ 2 + 4x + 7, root 2, y = 2x / 5x + 1 (5x + 1 is the denominator)

1: The formula of x ^ 2 + 4x + 7 is (x + 2) ^ 2 + 3 > = 3, so the original formula > = radical 32: using the inverse function method: by taking 5x + 1 as the denominator, we can get that x is not equal to - 1 / 5, and X = Y / (2-5y), so 2-5y is not equal to 0, then y is not equal to 2 / 5, and X is not equal to - 1 / 5, that is, Y / (2-5y) is not equal to - 1 / 5, and the solution is y is not equal to - 3 / 5

What functions are y = 2x-2, y = 5x ^ 2-4x, y = - x ^ 2, y = 6 / x? How to calculate the accuracy

Y = 2x - 2 linear function
Y = 5x & # 178; - 4x quadratic function
Y = - X & # 178; quadratic function
Y = 6 / X inverse scale function

What is a monotone increasing interval of function f (x) = (cosx) square-2 * [(cosx / 2) square]?

pai/2+k*pai

Given that the function f (x) is equal to SiNx times cosx plus the square of cosx minus half, find the monotone increasing interval of the period of the function!

f(x)=sinxcosx+(cosx)^2-1/2=0.5sin(2x)+0.5(1+cos2x)-1/2=0.5(sin2x+cos2x)=0.5√2sin(2x+π/4)
Monotone increasing interval: 2K π - π / 2

The monotone decreasing interval of function f (x) = (1 / 3) ^ | cosx | on [- π, π] is____ ?

The function f (x) = (1 / 3) ^ x is a constant decreasing function greater than zero on R. only when | cosx | is a decreasing function, f (x) is an increasing function, while | cosx | on [- π, π] is a decreasing function only if x belongs to [- π / 2,0] and [π / 2, π]