Răspuns:
[tex] {7}^{x + 1} ( {7}^{2} - 7 - 1) = 41 \times {7}^{2x} [/tex]
[tex] {7}^{x + 1} \times 41 = 41 \times {7}^{2x} [/tex]
[tex]x + 1 = 2x \: = > x = 1[/tex]
[tex] {3}^{x} \times {4}^{x} ( {3}^{3} \times 4 - 5) = 1236[/tex]
[tex] {3}^{x} \times {4}^{x} \times 103 = 1236[/tex]
[tex] {3}^{x} \times {4}^{x} = 1236 \div 130[/tex]
[tex] {3}^{x} \times {4}^{x} = 12[/tex]
[tex] {3}^{x} \times {4}^{x} = {3}^{1} \times {4}^{1} = > x = 1[/tex]
