Răspunsuri

2014-10-31T13:14:43+02:00
A) 3*x-12=15 3 * x=15+123 * x=27x= \frac{27}{3} =9

b)5 ^{x} =255 ^{x} =5 ^{2} x=2

c) 4  ^{2x} =2  ^{4} ( 2 ^{2} )  ^{2x} =2  ^{4}  2 ^{2*2x}  =2  ^{4}   2 ^{4x}  =2  ^{4}   4x =4  x= \frac{4}{4} =1

d) 5x +3=285x =28-35x =25 x = \frac{25}{5} =5

e) 12-2x=6-2x=6-12-2x=-6 |   *(-1)2x=6x= \frac{6}{2} =3

f) x-5:5=5 *5x-1=25x=25+1=26