Question

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$(7pq + 4mn)^{2}$
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Answer 1

Answer:

7pq+4mn^2

here we should use the formula,

(a+b)^2=a^2+ab+b^2

= (7pq)^2+2×7pq×4mn+(4mn)^2

= 49p^2q^2+56pqab+16m^2b^2