2022-2023学年河北省石家庄市石家庄数学八上期末质量跟踪监视试题含解析

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2022-2023
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16■:CEᑖ/BCD,:,NBCD=2NDCE,,NBCD=2/E,.ZE=ZDCE,.CD//EF
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17.ZDEF=90°,/.ZF=90°-ZEDC=30°*(2)VZACB=60°,Z£DC=60°,.♦.EOC1z45..ED=DC=2,,NOE^=90°,N^=30°,.DF=2DE=4,:.EF=£DE=26.ூ8௃9⚪ὃ<1z45ḄᑨCxឋj{|345Ḅឋj⚪ḄᐵG}~30ḄᡠḄ3z1zḄ.25'>(1)(1+x—y)2*(2)(a+<-2)%(3)V᪆ூᑖ᪆௃(1)ᡂ᦮x-y=A,ᓽ
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18=A(A+2)+l=A2+2A+1=(A+l)2¸“A”¹=(/+3஻+l)2.ºᦪn{n+1)(/1+2)(஻+3)+1Ḅ¦8»¼᦮ᦪḄ¾.ூ?@௃A⚪¿⌕ὃDc¢ᑖ+ḄÀᳮ+᦮ÁºᐭÀ8+⚪ḄᐵP.26ஹ(5a2+3ab)m2,198m2ூᑖ᪆௃✌ᐜᑡ*▢ÅÆᑖḄ☢ÈḄ⊤ÊᓄÌ)¦.ூ/+௃+1ÍᓄḄ☢È>(3a+b)(2a+b)—(a+b)2-(5a2+3ab)m2³a=6,b=l´ÍᓄḄ☢È>5a2+3ab=5x62+3x6xl=198(m2)ூ?@௃A⚪Îᵨᑡºᦪ)¦ḄÏÐ?ᐵP8ᓄÌ´⌕.