Question

Ben is x cm tall.

Kieran is 8 cm taller than Ben.
Bianca is 2 cm shorter than Ben.
Write an expression, in terms of x, for the mean of their heights in centímetres.
Give your answer in its simplest form.

Answer 1

x + 2

Explanation:

Ben : x cm

Kieran: (x + 8) cm

Bianca: (x - 2) cm

Mean of their heights =
`(Sum of their heights)/(Number of people) = (x + (x + 8) + (x - 2))/(3)`

=
`(x + x + 8 + x - 2)/(3)` (Expand the brackets)

=
`(x + x + x + 8 - 2)/(3)` (Bring all the like terms together)

=
`(3x + 6)/(3)` (Simplify the two sets of like terms)

=
`(3(x + 2))/(3)` (Extract the common factor '3' in the numerator)

= (x + 2) cm (
`(3)/(3) = 1`)

Answer 2

hope this helps you understand !!