Answer:
about 30 seconds
Step-by-step explanation:
Alcohol sanitizer is good until the alcohol evaporates, about 30 seconds. It is a cleaner, that kills the pathogens already on your hands. If you recontaminate your hands, you need to reapply.
Answer:
x= -2-√11. or. x= -2 + √11
Step-by-step explanation:
solving quadratic equation by completing the square
x^2+4x-7=0
x^2+4x=7
x^2+4x + (4/2)^2=7 + (4/2)^2 ( adding (1/2 coefficient of x)^2 on both sides
x^2+4x + 4=7 + 4
x^2+4x + 4=11. factorize(x^2+4x + 4) into (x + 2)^2
(x + 2)^2=11
√(x + 2)^2= + - √11
x + 2 = + - √11
there are two different solution .
x + 2 = -√11. or x + 2 = + √11.
x= -2-√11. or. x= -2 + √11.
Answer:

Step-by-step explanation:
The sum you are trying to understand is this.

Remember that in general when you have a geometric series
you have that
and that equality is true as long as
.
Therefore here we have
and 
Therefore we can use the formula and

Answer:
Rig
Step-by-step explanation:
Answer:
umm...
Step-by-step explanation: