Question 1102429
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Since the problem asks you to find Eddi's age, it is probably easiest to let his age be the variable.<br>
Let x = Eddi's age
Then x-12 = his sister's age<br>
Write and solve the equation that says the sum of their ages is 58.<br>
{{{x + x-12 = 58}}}<br>
You should be able to finish from there.