The equation is .

Apply addition property of equality: Add 25 to each side.

                     (Apply additive inverse property: )

                           (Apply additive identity property: )

k = 55                                    (Add:  30+25= 55)

Check:

To check the solution, substitute k= 55 in original equation.

30 = 30                                 (Subtract: )

The statement is true.

To graph the solution on the number line:

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• First draw the number line.
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• Mark a dot at 55 on the number line.
\

The value of k = 55.