Question 863631
Are you sure? Doesn't sound like a teacher would assign work you didn't go over.
OK, first off name the variables.
There are two of them, I'll use A and B.
Now use the information to make an equation.
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"sum of two numbers is 58"
{{{A+B=58}}}
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"their difference is 12"
{{{A-B=12}}}
Now you have 2 unknowns and you have 2 equations. Perfect, now you can solve it.
Add the two equations together to eliminate B.
Sounding familiar?
{{{A+B+A-B=58+12}}}
{{{2A=70}}}
{{{A=35}}}
Now that you have one variable, use either equation to solve for the other.
{{{A+B+58}}}
{{{35+B+58}}}
{{{B=23}}}