\(A=\left(4x+5\right)^2-\left(3x-7\right)^2-\left(4x-1\right)\left(4x+1\right)\)
\(=\left(4x\right)^2+2.4x.5+5^2-\left[\left(3x\right)^2-2.3x.7+7^2\right]-\left[\left(4x\right)^2-1^2\right]\)
\(=16x^2+40x+25-\left(9x^2-42x+49\right)-\left(16x^2-1\right)\)
\(=16x^2+40x+25-9x^2+42x-49-16x^2+1=-9x^2+82x-23\)
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A=(4x+5)2-(3x-7)2-(4x-1)(4x+1)
=16x2+40x+25-9x2+42x-49-16x2+1
=(16x2-9x2-16x2)+(40x+42x)+(25-49+1)
=-9x2+82x-23
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