I got the answer x^2 + 49 from the question (x+7)^2.
But then i was told the answer was x^2 +14x+49.
could some explain the 14x pleas?
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It [I assume you mean 14x not 40x] because
You need to either memorise the result, use the binomial theorem or use the distributive property/FOIL.
Using the distributive property
Memorising that is a great timesaver in exams
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