Question

Determinatj numarul natural n , dau coroana!

Answer 1

Răspuns:

b) n = 10; c) n = 7

Explicație pas cu pas:

b)

${3}^{2n - 3} = {27}^{7} : {9}^{2} \iff {3}^{2n - 3} = {( {3}^{3} )}^{7} : {( {3}^{2} )}^{2} \\ {3}^{2n - 3} = {3}^{21} : {3}^{4} \iff {3}^{2n - 3} = {3}^{17} \implies \\ 2n - 3 = 17 \implies 2n = 20 \implies \bf n = 10$

c)

${5}^{3n + 1} = {25}^{11} \iff {5}^{3n + 1} = {( {5}^{2} )}^{11} \\ {5}^{3n + 1} = {5}^{22} \implies \\ 3n + 1 = 22 \implies 3n = 21 \implies \bf n = 7$