Упростить
1) (a+3)^2-6a
2) (4a+1)^2+8a+1
3) 14b^2-(4b+1)^2
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1) (a+3)²–6a = (a²+2×3×a+9)–6a = a²+6a+9–6a = a²+9

2) (4a+1)²+8a+1 = ((4a)²+2×4a×1+1²)+8a+1 = 16a²+8a+1+8a+1= 16a²+16a+2

3) 14b²–(4b+1)² = 14b²–((4b)²+2×4b×1+1) = 14b²–(16b²+8b+1) = 14b²–16b²–8b–1 = –2b²–8b–1