There are 20 children at a library. Six of the children have a averahe age of 5 years. The remaining children have a sverage age of 8 years. What is the average age of the children at the library?​

The average age of the children at the library is 7.1 years.

Step-by-step explanation:

Given,

Out of 20 children, six of the children have an average age of 5 years,

Thus, the sum of the ages of 6 students = 5 × 6 = 30

( Total sum of observations = Their Average × Total numbers of the observations )

Now, remaining students = 20 - 6 = 14,

Since, the remaining children have an average age of 8 years.

Thus, the sum of the ages of 14 students = 14 × 8 = 112,

Total sum of the ages of 20 students = 30 + 112 = 142

=142/20

= 7.1 years

The average is 7.1 years!

Step-by-step explanation:

6 children = average of 5 years

14 children = average of 8 years

hello from mrbilldoesmath!

answer:   (7x + 6y) ( 49x^2 - 42xy + 36y^2)

discussion:

in general, the factorization of a^3 + b^3 is

a^3 + b^ 3 = (a + b) ( a^2 - ab + b^2)

in our case note that 343 = 7^3 and 216 = 6^3 so the equation becomes:

343x^3 + 216y^3 = (7x)^3 + (6y)^3

if you think of a (above) as 7x and b as 6y the factorization becomes

343x^3 + 216y^3 =

((7x + 6y) (   (7x)^2 - 7x*6y + (6y)^2)   =

(7x + 6y) ( 49x^2 - 42xy + 36y^2)

you,

mrb

(a + b) (a^2 - a b + b^2)