Question

rezolvati:
a) 3 ori x-12=15
b) 5 la puterea x=25
c) 4 la puterea 2x=2 la puterea 4
d) 5 ori x +3=28
e)12-2 ori x=6
f) x-5:5=5 ori 5

Answer 1

a)$3*x-12=15$⇒$3 * x=15+12$⇒$3 * x=27$⇒$x= \frac{27}{3} =9$

b)$5 ^{x} =25$⇒$5 ^{x} =5 ^{2}$⇒$x=2$

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) $5x +3=28$⇒$5x =28-3$⇒$5x =25$⇒$x = \frac{25}{5} =5$

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

f) $x-5:5=5 *5$⇒$x-1=25$⇒$x=25+1=26$