Tell you what I'll do: I'll show you the work, for two of them.
Then, knowing how to do it, you'll find the answers.
Deal ?
#1). n + (-13) = -12
Remove the parentheses
on the left side: n - 13 = -12
Add 13 to each side: n = 1
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#3). -15 + n = 3
Add 15 to each side: n = 18
OK. Look those over, understand how they're done, then TAKE IT !
