Answer:
4 hours to pay the same amount
and aif you want a 3 hours work you should get carpenter A
Step-by-step explanation:
[tex]50x = 20 + 45x \\ 5x = 20 \\ x = 4hours \\ [/tex]
carpenter A for 3 hours:
[tex]50 \times 3 = 150dollars \\ [/tex]
carpenter B for 3 hours:
[tex]20 + 45 \times 3 = 155dollars[/tex]