x^2-kx+21=0

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Solution for x^2-kx+21=0 equation:


Simplifying
x2 + -1kx + 21 = 0

Reorder the terms:
21 + -1kx + x2 = 0

Solving
21 + -1kx + x2 = 0

Solving for variable 'k'.

Move all terms containing k to the left, all other terms to the right.

Add '-21' to each side of the equation.
21 + -1kx + -21 + x2 = 0 + -21

Reorder the terms:
21 + -21 + -1kx + x2 = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -1kx + x2 = 0 + -21
-1kx + x2 = 0 + -21

Combine like terms: 0 + -21 = -21
-1kx + x2 = -21

Add '-1x2' to each side of the equation.
-1kx + x2 + -1x2 = -21 + -1x2

Combine like terms: x2 + -1x2 = 0
-1kx + 0 = -21 + -1x2
-1kx = -21 + -1x2

Divide each side by '-1x'.
k = 21x-1 + x

Simplifying
k = 21x-1 + x

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