10.1-10.2 习题课-2021-2022学年八年级下册数学【拉网提优大小卷】苏科版

∴.EF=BE+DF 10.3习题课(1) 1B2.C3B4B5.C6..86 3 9.音10. -2 1山.（①）原式=6a66a66ab 2b2 a=2-a (2)如图，由(1)知，△ADE≌△ABE(SAS), (2)原式= y(x-y) (x+y)(x-y) (x+y)(x-y) ∴.AE=AE,∠DAE=BAE, xy-y-zy 3y2 设BE=x,DF=y, （x+)(x-)x2-y; .正方形ABCD的边长为1， (3)原式= 2p-3g+2p+3g 4p .CE=1-x,CF=1-y. (2p+3q)(2p-3q)4p2-9g; ,△CEF的周长为2， .CE十CF十EF=2, (4)原式=a-a2-11 a-l a-Ia-1i ∴.1-x+1-y+EF=2, 2 2(y-1) ..EF=x+y=BE+DF=DE'+DF=E'F. (AE=AE, (5)原式=y+1)(y-y+1)(y) y+1 -3y+3 3 在△EAF和△EAF中，EF=EF, (y+1)(y-1)(y+1)(y-1)y+1 AF-AF, (6)原式=，二2十+x 2x-2 .∴.△EAF≌△EAF(SSS), x(x-1) x(x-1) x(x-1) ∴.∠EAF=/EAF, ∴∠DAE+∠DAF=∠BAE+∠DAF=∠EAF. x-2+x2+x-2x十2= :ZDAF+∠EAF+∠BAE=90°， x(x-1) (x-1)- 12.(1)② ../EAF=45°. (2)丢掉了分母 第10章分式 (3)原式= x-4 2(x-2) 10.1~10.2习题课 (.x+2)(x-2) -x十2)(x2)= x-4-2x+4 x 1.C2.A3.A4.A5.B6.D7.28.6x2y2 (x+2)(x-2) (x+2)(x-2) 义专0器总 11.-1或-312.18 13.4)原式=+2》)3=1- x+2 x+2 13.(1:分式没意义， (2)原式=2x-2+1_2+1)(x1)+1=2(x+1)+ x-1 x-1 .x-1=0,解得x=1. 1 (2)分式2+4 -有意义， x-1 ,分式的值为整数，且x为整数， ∴.x一1≠0，即x≠1. x一1=士1， (3):分式的值为0， x=2或0. 牛0解得=-2 10.3习题课(2) 1.原式=15_4-15=-1 H原式a)g 5a5a a-2b 2.原式=c++4+4_24士a=2a: 把a=2.6=号代入，原式 2+2×(-号)1 a十2 a十2 a+2 2a 1 2-2×(-2)3 3.原式=a+2)a-2-a+2=a+2a-2) a-2 a+2 1 15.(1)工=b.y= (a+2)(a-2)(a+2)(a-2)a-2 ac abe'be abci 4.原式= 2(x-1) x+5 3.x+3 2二)20r+- (x+1)(x-1)F(x+1)(x-1)-(x+1)(x-1) 3 x(x-3) 2-1 2x+6-2(x+3)(x-3) (3) 4(m+3) 原式号 y(y-x) x2-y x2-y2 m-32(m+3)(m-3), m-3 x十y 2(m+3)2(m+3)(m-3) x2 1 =x-1-x2+1 16.ab=1 be1 ac 1 6原武=D+D x(x-1) a+b-3'b+c=4'a+c=5’ ∴+-3+6-4,+-5 -x(x-1D=-1; x(x-1) 上述三式相加可得2+号+2-12， 7原式-之 2x=1; y-xy-xy-x 8.原式= 2(x+3) 12 2+2+1=6, 2(x+3)(x-3) 2(x+3)(x-3) b (x-1)(x-3)-x2+6x-9 (.x-3)2 bcactab-6. 2(x+3)(x-3)=2(x+3)(x-3)=-2(x+3)(x-3)= abc 73 abc 1 abbctac6 2(x+3) (x-1)2 1x一11 9原武=x十-D十市一++市千 97- 10.原式=a+2g-2)-4-2=a-2-4-2=-4 a+2 10原式票，兴，”-： 10.4习题课(1) (2)原式 6 a-3 1,原式=a十2)2 a2_a(a+2)_a2+2a (a+3)(a-3) +(a+3)(a-3) a(a-1)a+2a-1 a-1 a+3 2.原式=2g.15c2二54 (a+3)(a-3)a-3 3c3·6a8-3c9 3.原式=4a+). (3)原式-长·品-品 15a2b12a 5ab (a+b)(a-b)a-b5 (4)原式=x2(寸22.(x士2-2-2y 4.原式=a，·a十1)(a-)_a十1 (x+y)2 x+2y x+y a(a-1)a-1 业原式=·吊+中中西十 1 1 41 5原式=1÷+a-2