a) 3x -2x =7 x=7 (s-au înmulțit ambii membrii ai ecuației cu 6)
b) 4 + 3x + 3 = 30 - 4 +x 3x - x = 19 2x = 19 x = 19/2
c) 1/4·{ 1/4·[1/4·(1/4·x + 1) +4] +1} = 5 - 4 = 1
1/4·[1/4·(1/4·x +1) + 4] +1 = 1÷1/4 = 1·4/1 = 4
1/4·[1/4·(1/4·x + 1) +4] = 4 -1 = 3
1/4·(1/4·x +1) + 4 = 3 ÷1/4 = 3·4/1 = 12
1/4·(1/4·x + 1) = 12 - 4 = 8 1/4·x + 1 = 8 ÷1/4 = 8·4/1 = 32
1/4·x = 32 -1 =31 x = 31 ÷1/4 = 31·4/1 = 124
d) [ 2/3·x + 2x - 1/3 = 4-2x - 2 +11/3 ]×3 ⇒ 2x + 6x - 1 = 6- 6x + 11 2x +6x +6x =12 ⇒ 14x = 12 x =12/14 = 6/7 s-ar putea ca eu sa nu fi inteles corect textul; verifica, dar mersul rezolvarii nu se va scimba
e) 37/3÷{[11/4 ÷(5/3 + 15/8·x )]·8/11 + 5/3} =5
[11/4÷(5/3 + 15/8·x)]·8/11 + 5/3 = 5/1×3/37 = 15/37
[11/4÷(5/3 + 15/8·x)]·8/11 = 15/37 - 5/3 = - 140/111
11/4÷(5/3 + 15/8·x) = -140/111·11/8 = - 385/222·
5/3 + 15/8·x = -385/222× 4/11 = - 35·2/111 = -70/111
15/8·x = -70/111 - 5/3 = - 255/111 x= -255/111×8/15 =-136/111 VERIFICA !!!!1