Ответ:3) 16; 4)√x-√y;
Объяснение:
3)
1) (6^1/2+2^1/2)²=(6^1/2)²+2×6^1/2×2^1/2+(2^1/2)²=6+2×(12)^1/2+2=8+2×(12)^1/2
2) (6^1/2-2^1/2)²=(6^1/2)²-2×6^1/2×2^1/2+(2^1/2)²=6-2×(12)^1/2+2=8-2×(12)^1/2
3) 8+2×(12)^1/2+(8-2×(12)^1/2)=8+2×(12)^1/2+8-2×(12)^1/2=16
4) (x-y)/(x^1/2+y^1/2)=(x^1/2+y^1/2)×(x^1/2-y^1/2)/(x^1/2+y^1/2)=x^1/2-y^1/2=√x-√y;
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1)a8=4,4,a10=12,1
a10=a8+2d,2d=a10-a8=12,1-4,4=7,7,d=7,7:2,d=3,85
2)a5=8,7,a8=12,3
a8=a5+3d, 3d=a8-a5=12,3-8,7=4,6,d=4,6:3=46/30=23/15,d=23/15