Manuel ate lunch in 5 minutes. How many seconds is this?

300 seconds

Step-by-step explanation:

1 minute= 60 seconds

5 x 60 = 300

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!