Question

3 la puterea 8-3 la puterea 6=x la puterea 3,atunci: x <15 sau x=16 sau x=17 sau x mai mare sau egal cu 18

Answer 1

${3}^{8} - {3}^{6} = {x}^{3} \\ \\ ( {3}^{2} - 1) \times {3}^{6} = {x}^{3} \\ \\ (9 - 1) \times {3}^{6} = {x}^{3} \\ \\ 8 \times {3}^{6} = {x}^{3} \\ \\ {x}^{3} = 8 \times {3}^{6} \\ \\ {x}^{3} = 8 \times 729 \\ \\ {x}^{3} = 5832 \\ \\ {x}^{3} = {18}^{3} \\ \\ x = 18 \\ \\ = > x ≥ 18$