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Solve one-step addition equations

An addition equation represents an unknown quantity combined with a known addend to produce a known sum, in forms such as x+a=bx+a=b or a+x=ba+x=b, with values including integers, fractions, and decimals. Solving preserves equality by subtracting the same addend from both sides, or applying its additive inverse, and the solution can be verified by substitution; the scope is one-step equations with coefficient 1, not multi-step equations, distribution, or variables on both sides.

Detailed Explanation: Solve one-step addition equations

To solve an addition equation, use subtraction to undo the addition. Subtract the same number from both sides so the equation stays balanced.

Solve:

x+7=19x+7=19
  1. The number added to xx is 77. Subtract 77 from both sides:
x+7−7=19−7x+7-7=19-7
  1. Simplify:
x=12x=12
  1. Check the answer by substituting 1212 for xx in the original equation:
12+7=1912+7=19

Since the statement is true, the solution is:

x=12\boxed{x=12}

Learn by doing: Solve one-step addition equations

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One-Step Equation - Addition - Solve


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