When the square of x equals 27, what is the value of X + 1 / x?

When the square of x equals 27, what is the value of X + 1 / x?

x=±3√3
X+1/X
=(x^2+1)/x
=28/x
=±28/3√3
=±28√3/9
X+1/X=±28√3/9

Minus five x + fifteen x is less than or equal to minus one

The original formula is equal to minus three fifths x + one fifteenth X and less than or equal to - 1
Equal to minus two fifths, X is less than or equal to - 1
X ≥ 15 / 2

X-5 / 8x equals 90, x equals how much?

X-5 / 8x equals 90
3/8*X=90
X=240

Let the real number x satisfy the square of equation (X-2) + (KX + 2) = 4, and find the maximum value of K

(1+k²)x²+(4k-4)x+4=0
∵ x is a real number
The discriminant △ = (4k-4) &# 178; - 16 (1 + K & # 178;) ≥ 0
The solution is k ≤ 0
The maximum value of K is 0

If the equation (a-b) x square-8x + B = 0 of X has real roots, then the maximum value of integer a is

Detailed answers

(xsquare - 4x + 1 / 4) - (xsquare - X / 4) + (2x + 1 / 4)

(xsquare - 4x + 1 / 4) - (xsquare - X / 4) + (2x + 1 / 4)
=X^2-4X+1/4-X^2+X/4+2X+1/4
=-2X+X/4+1/2
=-7X/4+1/2

Evaluation: 3x2-3 (13x2-2x + 1) + 4, where x = - 2

3x2-3 (13x2-2x + 1) + 4 = 3x2-x2 + 6x-3 + 4 = 2x2 + 6x + 1. When x = - 2, the original formula = 2 × (- 2) 2 + 6 × (- 2) + 1 = - 3

Find the maximum value of square - 2x - 5 of quadratic function y = x on X ≥ 0 and ≤ 3

First of all, we know that it is a function with an opening upward and has a minimum value, so we first choose the axis of symmetry or the closest - B / 2A = 1 in this Fan Wei, so the minimum value is - 6

Prove that (square of x) + (square of Y) + 5 is greater than or equal to 2x + 4Y
To prove that (square of x) + (square of Y) + 5 is greater than or equal to 2x + 4Y

X & sup2; + Y & sup2; + 5 - (2x + 4Y) = (X & sup2; - 2x + 1) + (Y & sup2; - 4Y + 4) = (x-1) & sup2; + (Y-2) & sup2; the square is greater than or equal to 0, so (x-1) & sup2; + (Y-2) & sup2; > = 0, so x & sup2; + Y & sup2; + 5 - (2x + 4Y) > = 0, X & sup2; + Y & sup2; + 5 > = 2x + 4Y