Explicație pas cu pas:
[tex]128 \times 168 = {2}^{x} \times {3}^{y} \times {7}^{z}[/tex]
[tex]126 = {2}^{1} \times {3}^{2} \times {7}^{1}[/tex]
[tex]168 = {2}^{3} \times {3}^{1} \times {7}^{1}[/tex]
=>
[tex]{2}^{4} \times {3}^{3} \times {7}^{2} = {2}^{x} \times {3}^{y} \times {7}^{z}[/tex]
=>
[tex] x = 4 \\ y = 3 \\ z = 2[/tex]
=>
[tex]x + y + z = 4 + 3 + 2 = 9[/tex]
