The equation is 56 = 78.9 + p.

Apply addition property of equality: If a = b then a + b = b + c.

56 + 78.9 = 78.9 + 78.9 + p    (Add 78.9 to each side)

56 + 78.9 = p                (Apply additive inverse property: 78.9 + 78.9 = 0)

p = 134.9                      (Add: 56 + 78.9 = 134.9)

Check:

To check the solution, substitute p = 134.9 in original equation.

56 = 78.9 + p 56 = 78.9 + 134.9

56 = 56                           (Add: 78.9 + 134.9 = 56)

The statement is true.

Graph the solution on number line.

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• First draw a number line.
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• Mark a dot at 134.9 on  the number line.
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The value of p = 134.9.