Evaluate
\left(a-4b\right)\left(7a+b\right)
Expand
7a^{2}-27ab-4b^{2}
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7a^{2}-28ab+ba-4b^{2}
Apply the distributive property by multiplying each term of 7a+b by each term of a-4b.
7a^{2}-27ab-4b^{2}
Combine -28ab and ba to get -27ab.
7a^{2}-28ab+ba-4b^{2}
Apply the distributive property by multiplying each term of 7a+b by each term of a-4b.
7a^{2}-27ab-4b^{2}
Combine -28ab and ba to get -27ab.
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