K - 10/2 = -7

K - 5 = -7 (perform the indicated division)

K = -2 (add 5 to both sides of the equation)

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Perhaps you intended this.

(K -10)/2 = -7 (parentheses are used to identify the numerator)

K -10 = -14 (multiply both sides of the equation by 2

K = -4 (add 10 to both sides of the equation)

K - 5 = -7 (perform the indicated division)

K = -2 (add 5 to both sides of the equation)

_____

Perhaps you intended this.

(K -10)/2 = -7 (parentheses are used to identify the numerator)

K -10 = -14 (multiply both sides of the equation by 2

K = -4 (add 10 to both sides of the equation)