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8a^{2}+4
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8a^{2}+4
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a^{2}+4a+4-a\left(4-7a\right)
Use binomial theorem \left(p+q\right)^{2}=p^{2}+2pq+q^{2} to expand \left(a+2\right)^{2}.
a^{2}+4a+4-\left(4a-7a^{2}\right)
Use the distributive property to multiply a by 4-7a.
a^{2}+4a+4-4a+7a^{2}
To find the opposite of 4a-7a^{2}, find the opposite of each term.
a^{2}+4+7a^{2}
Combine 4a and -4a to get 0.
8a^{2}+4
Combine a^{2} and 7a^{2} to get 8a^{2}.
a^{2}+4a+4-a\left(4-7a\right)
Use binomial theorem \left(p+q\right)^{2}=p^{2}+2pq+q^{2} to expand \left(a+2\right)^{2}.
a^{2}+4a+4-\left(4a-7a^{2}\right)
Use the distributive property to multiply a by 4-7a.
a^{2}+4a+4-4a+7a^{2}
To find the opposite of 4a-7a^{2}, find the opposite of each term.
a^{2}+4+7a^{2}
Combine 4a and -4a to get 0.
8a^{2}+4
Combine a^{2} and 7a^{2} to get 8a^{2}.
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