1 2 xy 2(x + 1) 661 _______ _______ 2 r r 1 _____ : ______ a b 3a 662 _____ _______ a + ab _______ ab + b _______ : 3(x + 1) 3b 2x _____ r2 ___ ; [ 3y r 1 ] 2 r + s r + rs xy 2 2a 2b 2 a 2 c + 6c d 663 _______ __ 3 [ 2 x x xy 2 u 1 ______ u u ________ : q 2 2p + 2q 665 _____ _______ z + z _____ z+1 _______ : 5m + 5 2m 2 4z 12 2 z _2_ _____ [3; z 3] 4z 2 2 (r + 1) _______ r+1 _______ : a b ab 666 ______ _____ a+b a b 2 2 2 2a 2b _______ 4a 4b ________ : 12c + 12d 5c 5d _________ 668 _______ ab b a ab _______ _______ : 2a 4 1 669 ______ _____ a 2 _____ : (2a 4) 2 4c + 4d 20c 20d 2 2 2 5(a n) 4 4 2 3 6 6 x y +1 2 2 2 2 a+b 2 x y 1 2 2 2x + 8x + 8 _______ x 4 ___________ x 2 ax 2axy + ay 2 2 z 1 3z + 3 674 ________ _____ 2 4(x + 2) _4_ [ 5 ; 2(1 + a)] 2 2 2 4 4 2 b(a b) xy + 1 3 x3 y3 x + y 2xy 9x2 + 9y2 + 9xy 2 [ (a + b)(x y) x y 9(x y) 1 ____ [ x2y2 ] x xy 2 2 2 x 3x 33x + 35 __________ x x 6 ____________ x + 6x 16 677 _________________ 2 : 2 2 x + 4x + 4 678 [ x + 4x 5 x + 10x + 16 2 2 3 3 2 2 a2b2 4ab ______________ 2 ) a b2 + 7ab + 12 a b + 3ab 4 ____________________ a b + a b + 4ab 4 _____________ : ( 2 2 2 2 a b 16 3 3 a b + 3ab 4 2 2 2 x + y ___________ x y x 679 _______ 2 __________ 3 4 2 2 2 x y x 680 x + 2xy + y 4 2 2 3 2 x xy + y 2ab2 + b3 ________ 2a2b + ab2) a2 ab a + 9 6a b 2 2 2 ( a 4b 2 ] ab(1 ab) _______________ [ (a2b2 4)(ab + 3) ] [ab] a b 3a 3b ___________ a _______________ : 2 x 2 _1_ a a b a + ab _______________ : _________ a + 2a b 681 ______________ 2 2 (x 7)(x 3) ____________ [ x ] 2 (4a2b2 + 4ab3 + b4 a3 ] _____ _______ [ 3 ; 16 ] 2 3 ] 2 a 2b _3_; ___ [4 x y + xy ax + a _a_ 676 __________ : ______ 3 2 3 3 x + 2x + x ] 3(x + y) (x + 2) ____________ ; _______ 2 16x 16y (x y) _____________ _______ : 2 2 (xy 1) (x y x y + 1) (a ab + b ) _____________________ ____________ ; [ a3 a2b a2 + 2ab 3x + 3y 3xy x + y _____________ 675 ______ : 2 2 2 2 4a2b2 ] 4a2b2 a 4b _______ a b ______ z + 2z + 1 4z 4 x y (a + 2b) (a 2b) ______ a 2b _______________ ; a 2 ab + 2b (xy 1) _______ x y +1 ________ ax ay ______________ 3a + 3b 673 ________ 2 2 2 2 2 [ 2 1 a 6a b 12a b + 6a b 3 2 a 4 _____ 2b _______ 1 a ______ 3a b + 3ab 2a 2ab 672 ___________________ _________ 4 2 3 3 2 4 3 2 _______ 1 _____ ; [ a + 1 2(a + 1) ] 4a b 2 (a + b) [ 4 b2 ] a + ab 2 2 a n 4a + 4n 671 _______2 _______ 2 2 a _3_; __ 2 a 4b _______ : (a + 2b) 4a b (a + n) 2 a+1 a 4b 670 _______ (a + 2b) 2 2 2 [ 2 ab + b a 2 2 3(a + b) 1; _______ 2(x y) ] 3x2 3y2 9(x + y) x y a+1 [ab; (r + 1)(r 1)] (r 1)2 r 1 x + y (x y) 667 _____ _______ 2 2 x y 1 1 _____ ___ [ m + 1 ; 5u ] 15 + 15u 3u + 3 3q 6 2 2(x y) c + 6; _______ x2 ] 3 5 2m ___ 664 ______ p+q a ___ [ 2b ; 1] b 2x + 8 ______ x+4 ______ : c d ESERCIZI Operare con numeri e lettere a + ab 3a) 2 a 2b ______ a+b [a] 81